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The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000?*
ORIGINAL
A R T I C L E
The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000?* Ph Ricordeau, A Weill, N Vallier, R Bourrel, D Schwartz, J Guilhot, P Fender, H Allemand
S UMMARY
R Eu S U M Eu
Objectives: Our aim was to update available data concerning the prevalence and cost of diabetes in metropolitan France. Methods: We performed a retrospective study using patient reimbursement data from all the 128 local health offices (CPAM) in metropolitan France. We selected patients who received reimbursements for an oral hypoglycemic agent or insulin. Thus, 704,423 patients were studied by using 1998 data and 1,145,603 patients were studied by using data from 2000. The expenditures studied represented the total amount reimbursed by national health insurance to diabetic patients. The cost differential which could be attributed to diabetes was calculated by determining the difference between costs generated by diabetic patients to those generated by the rest of the population of the same age. Results: Between 1998 and 2000, the prevalence of diabetes treated in the population of affiliates covered by the general scheme increased from 2.78% to 2.96%. The total amount paid by the general scheme for care to diabetic patients (related to diabetes or not) was 5.710 billion euros in 2000 compared to 4.862 billion euros in 1998. The amount which can be attributed to diabetes alone can be estimated to be 2.414 billion euros in 2000 compared to 2.021 billion euros in 1998. After considering the impact of the increase in the number of treated diabetics, a modification in the modalities of medical care probably accounts for 183 million euros of the cost increase. Medical equipment (self blood glucose monitoring devices, reagent strips, finger lancets....) accounts for 39.3% (72 million euros) of this cost differential, medications account for 34.4% (63 million euros) and nursing care 16.9% (31 million euros). There was no change in the cost of diabetes with relation to expenses for medical consultations.
Prévalence et coût du diabète en France métropolitaine : quelles évolutions entre 1998 et 2000 ?
Key-words: Cost analysis z Diabetes Mellitus z France z Pharmaco-epidemiology z Prevalence. Ricordeau Ph, Weill A, Vallier N, Bourrel R, Schwartz D, Guilhot J, Fender P, Allemand H. The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000? Diabetes Metab 2003,29,497-504
Objectif : Notre objectif était de faire le point sur les données disponibles portant sur la prévalence et le coût du diabète en France métropolitaine. Méthodes : Nous avons conduit une étude rétrospective portant sur les données de remboursement des 128 CPAM de France métropolitaine. Nous avons sélectionné les patients qui ont reçu au moins un remboursement d’hypoglycémiant oral ou d’insuline. Ainsi, 704 423 patients ont été étudiés en utilisant les données de 1998, et 1 145 603 patients en utilisant les données de 2000. Les dépenses étudiées représentent le montant total remboursé par l’assurance maladie aux patients diabétiques. Le différentiel de coût qui peut être attribué au diabète a été calculé en déterminant la différence entre les coûts générés par les patients diabétiques et ceux générés par le reste de la population du même âge. Résultats : Entre 1998 et 2000, la prévalence du diabète traité dans la population relevant du régime général a augmenté de 2,78 % à 2,96 %. Le montant total des dépenses du régime général pour les soins donnés aux patients diabétiques (liés au diabète ou non) a été de 5,710 milliards d’euros en 2000 comparés à 4,862 milliards d’euros en 1998. Le montant attribuable au diabète peut être estimé à 2,414 milliards d’euros en 2000 comparés à 2,021 milliards d’euros en 1998. Après neutralisation de l’impact de l’augmentation du nombre de diabétiques traités, l’accroissement des coûts s’expliquait pour 183 millions d’euros par une modification des modalités de prise en charge des patients. Le matériel médical (appareils d’autosurveillance glycémique, bandelettes, autopiqueurs...) représente 39,3 % (72 millions d’euros) de ce différentiel de coût, les médicaments représentent 34,4 % (63 millions d’euros) et les soins infirmiers 16,9 % (31 millions d’euros). Il n’y a pas eu de variation du coût du diabète en rapport avec les honoraires médicaux. Mots-clés : Analyse de coût z Diabète sucré z France z Pharmaco-épidemiologie z Prévalence.
Address correspondence and reprint requests to: Ph Ricordeau. CNAMTS, 66, avenue du Maine, 75694 Paris Cedex 14, France. [email protected] *A French version of this article has already been published in the Revue Médicale de l’Assurance Maladie, 2002, vol. 33 Direction du Service médical de l’Assurance maladie (CNAMTS), CNAMTS, Paris, France.
Received: May 26th, 2003; accepted: June 15th, 2003 Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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U
sing the momentum of the Saint Vincent Declaration [1], the three main French healthcare funds launched a multi-annual program in public health in June 1999 aimed at improving the clinical management of type 2 diabetes mellitus. This program used national health insurance’s database [2-4] and was designed to evaluate the clinical management of diabetic patients by quantifying the reimbursements they received for care. The statistical study performed at that time also provided an estimation of the total amount of care reimbursed to patients in 1998 by the entire general healthcare scheme which covers 83.4% of the French population [5], irrespective of the type of diabetes they had: 4.862 billion euros of which 2.021 billion could be attributed to care for diabetes mellitus [6]. This public health program consisted in promoting the practice guidelines which had been published during the first trimester of 1999 by the National Agency for Accreditation and Health Evaluation (ANAES) [7] and the French Agency for the Security of Health Products (AFSSAPS) [8] to healthcare professionals. Accordingly, between June and December 1999, national health insurance’s salaried medical advisors (médecins conseils) encountered or directly contacted nearly 23,000 primary care physicians in order to present them with the guidelines. This strategy proved to be efficacious since a subsequent study, performed using an identical methodology and 1998 data, demonstrated that, in 2000, the medical management of patients had shown some improvement and that the recorded improvement was at least partially related to national healthcare’s program [9]. A remaining task was to update available data on prevalence and especially on the cost of diabetes for the year 2000 by measuring the contemporary changes in the results of the program.
Method We have already described in detail the method we used in 1998 to identify treated diabetic patients and to calculate total patient reimbursements (supplement in the September 2000 issue of Diabetes & Metabolism) [6, 10, 11]. In particular, the supplement clearly describes how data was gathered, the statistical analysis used, how results were validated, the calculation of correction coefficients and how the results were weighted. Interested readers are invited to consult the above-mentioned issue. The method used to update this data was rigorously identical to the previously described method. Here, we present a synthesis of the method and its key principles.
Data gathering By using the information contained in the computer databases of each local health office (CPAM) stored in the 498
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Table I
Oral hypoglycemic agents used in France to identify patients. Therapeutic Class Sulfonylureas
Biguanides Glinides Alphaglucosidase inhibitors
Common international designation Carbutamide, Chlorpropamide, Glibenclamide, Glibornuride, Gliclazide, Glimepiride, Glipizide, Tolbutamide Metformin Répaglidin Acarbose, Miglitol
health fund’s information system (SIAM)1, the general scheme for salaried workers has access to an important database containing all benefits reimbursed to affiliates in addition to precise information on prescribed laboratory tests and medications which are identified by specific codes. Due to the unique and exhaustive relationship between treated diabetes mellitus and the medications prescribed for this disorder, this database can be used to identify diabetics receiving treatment. Consequently, information was gathered by launching a series of identical parametric computer requests into the databases of each 128 local health offices (CPAM) in metropolitan France during the first trimester of 1999 (for 1998 data) and during the first trimester of 2001 (for 2000 data). Due to technical difficulties, information concerning the total cost of care given to patients in 1998 was only available from 110 of the 128 CPAMs. The list of oral hypoglycemic agents obtained from this selection included biguanides, sulfonylureas, alpha-glucosidase inhibitors as well as, for the year 2000, repaglidin, which was commercialized in March 2000. The list did not include adjuvants such as benfluorex (Tab I). In this study, the population source from which statistical individuals were obtained was defined by all affiliates in the general scheme for salaried workers stricto sensu (affiliates and eligible family members) who received reimbursement for at least one diabetes medication during the three-month inclusion period which was identifiable by its CIP2 code: oral hypoglycemic agents (OHA) or insulin. The general scheme stricto sensu excludes local supplemental health funds (supplemental funds covering state-employed teachers, government employees and officials, post office workers, students, etc.) which represent 16% of the population covered by the general scheme. During the validation phase, 0.9% of the statistical individuals were excluded (6,130 out of 1. The National Committee on Information and Liberty (CNIL) authorized the national health fund to add to SIAM data for precisely identifying medications and laboratory tests reimbursed to patients. 2. The CIP code (Inter Pharmaceutical Club) is a identification number corresponding to each pharmaceutical product in France.
Prevalence and cost of diabetes in France
710,553) in the calculations used to study 1998 data and 0.5% (6,107 out of 1,151,710) in the calculations used to study 2000 data. These exclusions mainly concerned statistical individuals for whom no information on age and/or sex was available (the majority of the cases involved patients who died during the inclusion period or who had changed healthcare funds). Overall, we enrolled 704,423 diabetics treated during 1998 and 1,145,603 diabetics treated during 2000.
Statistical analysis Correcting for patient enrollment and weighing of results
In the beginning of the year 2001, the pharmacy coding system was incompletely integrated into local health office computer systems: the rate was 89% over the entire national territory but the actual percentage was different in each individual CPAM. Two years earlier, the rate was 70.3%, thus explaining the difference in the number of patients enrolled in 1998 and 2000. In fact, the number of diabetics identified by the coding system month after month was proportional to the progressive increase in the integration rate; indirectly, this suggested that the population of patients selected by the pharmacy coding system was representative [11]. In order to compare the results obtained from 1998 and 2000 data, we corrected for the number of diabetics identified in the reimbursement database by comparing the rate of integration of the CIP code in each CPAM individually. In addition, for 1998 data, the average costs found in the 110 CPAM included in the study were applied to the enrolled diabetics identified in the databases of the 18 CPAMs3 for whom cost information was lacking. Finally, in order to facilitate the analysis and obtain results for the general scheme overall and not solely for the general scheme stricto sensu, even if the last-mentioned represents 84% of all affiliates, we applied the prevalence seen in this population to the total number of affiliates in the general scheme (49,208,966 individuals on December 31, 1999) [5, 12]. Calculation of the cost of care given to diabetics
The economic data used was the total amount reimbursed by the general fund during the 12-month period preceding the enrollment period, irrespective of the disorder motivating reimbursement. These expenditures only concerned the general fund’s direct costs for treating diabetes and did not include income-replacement benefits given to salaried affiliates (sick pay, annuities or pensions). Calculations were based on expenditures for all diabetics irrespective of the kind treatment they received (insulin alone, insulin combined with oral hypoglycemic agents or oral hypoglycemic agents alone). In this article, we present the 3. The CPAM of Calvados, l’Orne, la Manche, L’Eure, Elbeuf, Dieppe, Le Havre, Rouen, Côtes d’Armor, Bouches-du-Rhône, les Ardennes, la Marne, l’Aube, la HauteMarne, Longwy, Nancy, la Meuse and les Vosges.
results in aggregate form. Out-patient expenses included reimbursements for doctors’ fees (medical consultations but excluding examinations performed in public institutions), medications and laboratory tests, nursing care (injections, bandages, care to dependent persons), medical equipment (syringes, reagent strips, self blood glucose monitoring devices, finger lancets...), patient transportation (taxis, taxiambulances, ambulances...) as well as an expense category containing other out-patient expenditures (physical therapy, dental care, eyeglass care...). Hospitalization expenditures were comprised by hospitalization costs in private facilities (including doctors’ fees) as well as costs related to hospital stays in public institutions receiving an annual endowment. Statistical treatment of data consisted in calculating the average amount reimbursed to each patient, for whatever disorder, diabetes-related or not, followed by an average cost differential obtained by subtracting the average amount reimbursed to diabetic patients from the average amount reimbursed, in the same age-group, to the entire population of affiliates who received at least one reimbursement during the course of the year. Finally, by applying the average patient costs for 1998 to the number of diabetics in the general fund in 2000, we were able to estimate in the expenditure increase due to diabetes mellitus, the effects of the change in the number of diabetics treated on the one hand and, on the other hand, the changes in the medical management of these patients. Tools and statistical methods
We used SPSSt version 9.0.1 software and an IBMt Pentium III computer located in the office of the direction of the medical service of the national health fund for salaried workers (CNAMTS) for treating the anonymous data obtained. We utilized classic descriptive statistical methods including adjustments for patients’ ages. Confidence intervals are not given with the results since the study population can be considered exhaustive and does not represent a sample. We did not test the differences in the average costs for diabetes mellitus. Indeed, since the survey population was so large, any difference, even a very small one, could be significant in the statistical sense of the word without reflecting any real difference with perceptible public health consequences.
Results
Prevalence For 2000 data, the survey population contained 1,145,603 diabetic patients who were identified by using the reimbursement database of the CPAMs. After correcting for the pharmacy coding integration rate, this corresponded to a population of 1,230,851 diabetic affiliates of the general health fund stricto sensu, or a prevalence of 2.96% if all treatment modalities are considered (14.7% of treated diabetics Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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were treated with insulin alone, 5.3% with both insulin and oral hypoglycemic agents (OHA) and 80.0% OHA without any insulin). All treatment modalities combined, in 1998 the prevalence was 2.78%. 14.7% of diabetics were treated solely with insulin, 4.3% with a combination of insulin and oral hypoglycemic agents (OHA) and 81.0% OHA alone with no insulin at all [10]. Thus, between 1998 and 2000, the prevalence of treated diabetes in the population covered by the general health fund stricto sensu increased by an annual average of 3.2%. In order to calculate the health fund’s expenditures for the management of diabetes, these different prevalence rates were applied to the overall population covered by the general fund.
Health fund expenditures for delivered drug prescriptions and care given to diabetic patients In 2000, the general fund’s total expenditures for delivered drug prescriptions and care given to diabetics was 5.710 billion euros; 2.398 billion of this amount covered in-hospital care (42.0%) and 3.312 billion euros were spent on outpatient primary care (58.0%). In comparison, in 1998, total expenditures were 4.862 billion euros of which 2.164 billion euros covered in-hospital care (44.5%) and 2.698 billion euros were allocated to out-patient primary care (55.5%). Thus, over the two-year period, reimbursement to the general fund’s affiliates increased by 0.848 billion euros or an annual increase of 8.4%. 72.4% of this increase was for out-patient primary care (Tab II). The average annual increase in total expenditures per patient grew from 3,680 euros in 1998 to 3,914 euros in 2000 (an annual increase of 3.1%) or an increase of 234 euros per patient over the two-year period (Tab II).
Cost differential of diabetes for the health fund When taking into account the standardization of patient’s ages in 2000 and in 1998, diabetics cost4 the health fund an average of 1.7 times more compared to costs generated by the general population. In 2000, the health fund reimbursed an average of 1,655 euros per diabetic patient’s; 30.6% of this total (507 euros) was for in-hospital expenses and 69.4% (1,148 euros) was for care prescribed or delivered in out-patient primary care. In 1998, the health fund reimbursed an average of 1,529 euros to each diabetic patient: 32.8% of this total (502 euros) was for in-hospital expenses and 67.2% (1,027 euros) covered care prescribed or delivered in out-patient primary care (Tab III). By applying these results to the total number of diabetics identified in the general health fund, the overall cost generated by diabetics in 2000 can be estimated to be 2.414 billion 4. In this article, the cost differential is defined by the difference in health fund expenditures for total care to diabetic patient’s compared to expenditures for care to the general population (average expenditure per patient of the same age).
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Table II
Health fund expenditures for delivered prescriptions and care given to diabetic patients, for whatever disorder, in 1998 and 2000 (data for the general scheme in France). Average amount per patient (in euros) 1998 2000
Total amount (general scheme) (in billions of euros) 1998 2000
Out-patient primary care for... Doctors’ fees Medications Lab. Tests Nursing care α Med. equipment β Transportation χ Others δ
2,042
2,270
2,698
3,312
320 971 102 272 154 74 149
329 1,077 110 301 222 86 145
0,423 1,282 0,135 0,360 0,204 0,097 0,197
0,479 1,571 0,161 0,440 0,324 0,126 0,211
Hospital Stays
1,638
1,644
2,164
2,398
Total
3,680
3,914
4,862
5,710
α
Nursing care (injections, bandages, care given to dependent patients). β Medical equipment (syringes, reagent strips, self blood glucose monitoring devices....). χ Transportation (ambulance, taxi-ambulance, taxi). δ Other out-patient expenditures (physical therapy, dental care...).
euros for this population of which 1.675 billion euros were reimbursed uniquely for out-patient care and 0.739 billion euros for in-hospital expenses. Between 1998 and 2000, the health fund’s expenditures for diabetes increased by 393 million euros, or an increase of 19.4% (318 million euros for out-patient care and 75 million euros for in-hospital care) (Tab III). Of the 318 million euros spent on out-patient care, 134 million were for medications, 87 million for medical equipment, 57 million for nursing care, 13 million for laboratory tests and 13 million for doctor’s fees. Between 1998 and 2000, the cost of care to diabetics increased by 19.4%. More than half of this cost increase (10.3%) can be explained by the increase in the number of treated diabetics. After compensating for this effect, changes in the clinical management of these patients accounts for an increase of 183 million euros. An increase in expenses for medical equipment represented 39.3% (72 million euros) of this total, 34.4% (63 million euros) corresponded to expenses for medications, nursing care represented 16.9% (31 million euros) of this increase, 6.6% (12 million euros) went to patient transportation and finally, laboratory tests accounted for 2.7% (5 million euros) of the increase. The only explanation for the variation in the cost of doctors’ fees for diabetes between 1998 and 2000 was the increase in the number of treated patients.
Prevalence and cost of diabetes in France
Table III
Average cost differential per patient and total cost differential for the healthcare fund for diabetic patients treated in 1998 and 2000 (data from the general scheme in France). Average amount per patient (in euros) 1998 2000
Total amount (general scheme) (in billions of euros) 1998 2000
Out-patient primary care for... Doctors’ fees Medications Lab. Tests Nursing care α Med. equipment β Transportation χ Others δ Hospital Stays
1,027
1,148
1,357
1,675
95 527 57 187 113 27 21 502
95 570 60 209 162 35 17 507
0,125 0,697 0,075 0,248 0,149 0,035 0,028 0,664
0,138 0,831 0,088 0,305 0,236 0,051 0,026 0,739
Total
1,529
1,655
2,021
2,414
α
Nursing care (injections, bandages, care given to dependent patients). β Medical equipment (syringes, reagent strips, self blood glucose monitoring devices....). χ Transportation (ambulance, taxi-ambulance, taxi). δ Other out-patient expenditures (physical therapy, dental care...).
Discussion
The contributions of the survey A higher prevalence of diabetes mellitus in the French population
The prevalence of diabetes mellitus in the population of affiliates covered by the general health insurance fund increased an average of 3.2% per year between 1998 and 2000. For a start, this regular increase in prevalence, already predicted by epidemiologists, can be explained by demographic changes similar to those observed in other western countries: aging of the population, increase in longevity and the arrival, in the age-group carrying a high risk for diabetes, of the children born during the “baby-boom” [13]. Part of the prevalence increase can undoubtedly also be attributed to improved screening for the disease and sociological factors associated with life-style changes, particularly an augmentation in obesity and a general decrease in physical activity [14-16]. For these reasons, the World Health Organization (WHO) predicts a 35% increase in the worldwide prevalence of diabetes over the next few years [17]. Lowering of the diagnostic threshold between 1998 and 2000 [18, 19] from 1.40 g/L (7.8mmol/L) to 1.26 g/L (7.0mmol/L) may have also played a part in the prevalence increase even though, up until the present, numerous studies have concluded that a lowering of the diagnostic criteria should not appreciably modify the overall prevalence of diabetes mellitus [13, 20,
21]. On the other hand, the population survey performed in France between 1995 and 1997 in the three MONICA centers which gathered information on a number of laboratory test results, concluded that a reduction in the diagnostic criteria for fasting blood sugar could result in an important increase (X 2.2) in the number of diabetics identified in the 35 to 64 year-old age group [22]. The increase in prevalence of diabetes mellitus is not confined to France. Other studies, mostly performed in the United States [23, 24] show similar results with respect to both type 1 diabetes mellitus, whose incidence is increasing in wealthy countries [25], and type 2 diabetes mellitus. Thus, the number of patients in the United States with type 2 diabetes has already increased by 35% between 1993 and 1998 [23, 24]. The prevalence of diabetes in metropolitan France at the beginning of 2001 (2.96% in the population of affiliates covered by the general health insurance fund stricto sensu) is intermediate between the countries in Northern Europe, whose prevalence was estimated at 2.4% in the middle of the 1990s and who represent 90% of the total number of patients [13, 14], and the Mediterranean countries (Italy, Greece, Spain and Portugal) who have recorded a prevalence in excess of 4.0% [8]. The health fund’s expenditures for drug prescriptions and care delivered to diabetics in 2000
The general health fund reimbursed, all diseases combined, an average of 3,914 euros per patient in 2000; 1,655 euros of that amount was spent on the overall management of diabetes mellitus and its complications. This amount exceeds the estimate (3,064 euros) published in France in the multi-center European study known as CODE-2 [26]. In addition to the fact that CODE-2 studied reimbursements to patients in 1998, a number of other factors can explain the differences found between those results and our findings. In a previous publication, we have already discussed these factors: different patient recruitment (for example, only patients with type 2 diabetes were enrolled in the CODE-2 study), differences in the method used for information gathering and differences in the categories of expenses considered (the CODE-2 study excluded costs for patient transportation and for medical materials) [6]. If our results are compared to those found in other countries-mostly concerning the United States-expenditures in France appear to be lower even if comparisons of this kind are difficult due to important differences in the organization of care and disease management. Be that as it may, Brown et al. [27] followed 30,377 type 2 diabetics for from 1 to 8 years and found that, during the first eight years following the diagnosis, their care cost an average of $ 2,257 per year (in 1993 dollars) more than care to paired subjects. Elsewhere, Selby et al. [28] calculated the cost differential ($ 3,494 in 1994 dollars per patient per year) between diabetics and non-diabetics in a representative sample of the American population. These cost differentials Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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($ 2,257 for Brown et al. and $ 3,494 for Selby et al.) are greater than the cost differential found in our study (1,655 euros). The changes in expenditures between 1998 and 2000
First of all, the change in expenditures can be explained by the rapid increase in the number of treated diabetics, already mentioned above. Over two years, an additional 72 million euros were spent on prescriptions for medical equipment (including, notably, self blood glucose monitoring devices and reagent strips) even though present data suggest that self blood glucose monitoring does not help reduce glycated hemoglobin levels [29]. With our data, we were unable to identify the therapeutic drug classes mainly responsible for the 63 million euro increase in drug prescriptions. In the CODE-2 study, cardiovascular and lipid-lowering drugs represented the most significant part of the increase in expenditures for medications [26] and it is all together possible that prescriptions for these same medications played an important role in the increase in expenditures we found. Moreover, between 1998 and 2000, the percentage of patients receiving lipid-lowering drugs grew from 38.0% to 40.3% [9].
Limits and validity of our results Selection of diabetics by using the pharmacy coding system
This study was based on patient reimbursements during a fixed time period. By definition, the general health fund only has access to information concerning medications for which its affiliates have requested reimbursement. Some drug prescriptions may have never been filled if the patient already had a sufficient supply at home to meet his needs. However, by enrolling patients reimbursed during a threemonth period for this chronic disorder which generally requires monthly prescription pharmacy renewal, we can probably assume that the patient population receiving at least one prescription over the three-month period corresponds to the overall population of treated diabetics. On the other hand, the health fund’s information system is totally incapable of identifying patients whose diabetes is sufficiently controlled by life-style measures alone, a cohort which the High Committee on Public Health estimated at 10% of type 2 diabetics in 1998 [30] and, in addition, offers no information a fortiori on undiagnosed diabetics, whose numbers remain unknown. Even if, on the average, these patients utilize much less care than other diabetics, we still must consider the fact that our results fail to take into account their expenditures. If we consider the integration parameters of the pharmacy coding system into the health fund database, our results probably do not contain any selection bias related to incomplete integration of the coding system. Indeed, in addition to the large number of diabetics identified by the coding system (70.3% of all medications were coded in 1998 and 89.0% were coded in 2000), the progressive, almost propor502
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tional increase in the diabetic population compared to the integration rate of the coding system [11], strongly suggests that, for most local health agencies, the selected population was representative. Accordingly, there is no reason to believe that the costs generated by the diabetics who were excluded from our computer survey were different from those identified by the coding system. Determining the cost of diabetes mellitus
In determining total expenditures for diabetics, the health fund included amounts paid to facilities financed by global budgeting for hospital stays related to diabetes. However, part of these hospital stays are incompletely reported since some healthcare facilities file late and/or incomplete reports on individual patients, thereby depriving local health agencies (CPAM) of the necessary information. The magnitude of the unreported information is impossible to measure but this fact definitely results in an underestimation of the total cost for diabetes management. In addition, in calculating the cost differential due to diabetics, rigorous methodology would have required deducting data on the diabetic population from data on the overall population covered by the general scheme. Unfortunately, this in not possible with a computer database survey. Even if we take that fact into account, the bias introduced is undoubtedly minimal since diabetes has an estimated prevalence of 3% in the population covered by the general scheme. However, the calculation method we used introduced a more important bias, leading us to underestimate the cost differential attributed to diabetes due to the fact that we do not know the number of affiliates covered by the general scheme according to age-group and we based average costs on the amounts reimbursed solely to the cohort of patients who requested at least one reimbursement during the year (termed the population of “consumers”). But it just so happens that a study performed by the CREDES in 1995 found that 9.7% of the covered population does not utilize any healthcare resources during a given year [31]. Even if this “non-consumer” population only represents a slight percentage in the age-groups containing the highest prevalence for diabetes (3.6% between 65 and 79 years and 0.9% beyond that age), in our study, the average costs based on the reference population we used are definitely a little overestimated and, consequently, the cost differentials attributed to diabetes are somewhat underestimated. The choice of the method used
We limited our study to expenditures for affiliates of the general healthcare fund. In order to determine total reimbursements to all patients, it would have been necessary to include reimbursements in the other healthcare funds (mainly covering the agricultural profession, craftsmen and merchants) which cover 16.6% of the French population. The general fund’s database stored in local health agencies only records reimbursed benefits to patients and contains no clinical information or laboratory test results. Thus,
Prevalence and cost of diabetes in France
it is impossible to deduce the relative numbers of patients with type 1 and type 2 diabetes mellitus from the information available to the general health fund since, at the present time, essentially clinical criteria are used to differentiate the two forms [32]. It appears that an important proportion of authentic type 2 diabetics (estimated to be 50% by most authors) are treated with insulin in addition to oral hypoglycemic agents or sometimes with insulin alone; moreover, they often have the most severe forms of type 2 diabetes. Accordingly, it is probably not very relevant to differentiate the three therapeutic modes in order to perform a medicoeconomic study (in general, insulin-treated diabetics are the most expensive). The European CODE-2 study confirmed this notion: it found that insulin-treated diabetics utilized two times the direct health resources as diabetics treated solely with oral hypoglycemic agents (OHA) [26]. Our study was limited exclusively to the direct costs of diabetes mellitus and excluded indirect costs generated by income replacement benefits, disability pensions and premature mortality. In a 1997 American Diabetes Association study which enrolled an elderly and mostly professionally inactive population, indirect costs for diabetes were found to be greater than direct costs [33]. A comprehensive determination of the total cost of diabetes mellitus would also require taking into account parameters like the quality of life, which are difficult to measure: psychological, familial and social consequences [34, 35]. In witness, a study found that depression was more prevalent in a cohort of patients with type 2 diabetes than in a control group [36]. Finally, this study was not able to differentiate costs solely related to the clinical follow-up of diabetes mellitus (blood sugar control, screening for complications) from those attributed to its degenerative complications since local health office data provides no clinical information or laboratory test results. It just so happens that a number of studies addressing diabetes have shown that overall management costs are mostly due to the treatment of complications [25, 37-39]. In addition, the European CODE-2 study found that direct medical costs are multiplied by a factor of 2 when macrovascular complications are present and by a factor of 3.5 when both micro and macrovascular complications coexist [26].
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Weill A, Ricordeau P, Vallier N, Bourrel R, Fender P, Allemand H. Les modalités de suivi des diabétiques non insulino traités en France métropolitaine durant l’année 1998. Diabetes Metab, 2000, 26, 39-48.
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Caisse nationale d’assurance maladie des travailleurs salariés (CNAMTS). Échelon national du service médical. Programme de santé publique sur la prise en charge du diabète de type 2: La prise en charge des diabétiques exclusivement traités par hypoglycémiants oraux en 1998. Paris, 1999. 5. Caisse nationale d’assurance maladie des travailleurs salariés (CNAMTS). Études et Statistiques: la population protégée par les régimes de sécurité sociale. No43. Paris, CNAMTS, 1999. 6. Ricordeau P, Weill A, Vallier N, Bourrel R, Fender P, Allemand H. Le coût du diabète en France métropolitaine. Diabetes Metab, 2000, 26, 6, 25-38. 7. Follow-up of the type 2 diabetic patient excluding follow-up of complications. Recommendations of ANAES. Diabetes Metab, 1999, 25 Suppl 2: 1-64. 8. Treatment recommendations for type 2 diabetes. Agence Française de Sécurité Sanitaire des Produits de Santé (AFSSAPS). Diabetes Metab, 1999, 25 Suppl 6: 1-79. 9. Ricordeau P, Weill A, Bourrel R, et al. Programme de santé publique sur la prise en charge du diabète de type 2. Évolution de la prise en charge des diabétiques non insulinotraités entre 1998 et 2000. Caisse nationale d’assurance maladie des travailleurs salariés (CNAMTS), Direction du service médical. Paris, 2002. 10. Ricordeau P, Weill P, Vallier N, Bourrel R, Fender P, Allemand H. L’épidémiologie du diabète en France métropolitaine. Diabetes Metab, 2000, 26, 11-24. 11. Weill P, Ricordeau P, Vallier N, Bourrel R, Fender P, Allemand H. L’analyse des prestations remboursées par l’Assurance maladie: Matériel et Méthodes. Diabetes Metab, 2000, 26, 49-54. 12. Caisse nationale d’assurance maladie des travailleurs salariés (CNAMTS). Études et Statistiques: la population protégée par les régimes de sécurité sociale. No48. Paris, CNAMTS, 2001. 13. Delcourt C, Papoz L. Les différents types de diabète en France métropolitaine. Le diabète et ses complications dans la population française. Paris, INSERM, 1996, 13-33. 14. Fontbonne A, Simon D. Epidémiologie du diabète. Encycl Méd Chir (Editions Scientifiques et Médicales Elsevier SAS, Paris), Endocrinologie-Nutrition, 10-366-B, 2001. 15. Rocchini AP. Childhood obesity and a diabetes epidemic. N Engl J Med, 2002, 346, 11, 854-5. 16. Haut comité de la santé publique. Ministère de l’Emploi et de la Solidarité. La santé en France 2002. Paris, La documentation française, 2002. 17. Eschwege E. Epidemiology of type II diabetes, diagnosis, prevalence, risk factors, complications. Arch Mal Coeur Vaiss, 2000, 93, 13-7. 18. The expert committee on the diagnosis and classification of diabetes mellitus: report of the expert committee on the diagnosis and classification of diabetes mellitus. Diabetes Care, 1997, 20, 1183-97. 19. Drouin P, Blickle JF, Charbonnel B et al. Diagnostic et classification du diabète sucré, les nouveaux critères. Diabete Metab, 1999, 1, 72-83. 20. Decode study group on behalf of the European diabetes epidemiology study group. Will new diagnostic criteria for diabetes mellitus change phenotype of patients with diabetes? Reanalysis of European epidemiological data. Br Med J, 1998, 317, 371-5. 21. Balkau B. The DECODE study. Diabetes Metab, 2000, 26, 282-6. 22. Gourdy P, Ruidavets JB, Ferrieres J, et al. Prevalence of type 2 diabetes and impaired fasting glucose in the middle-aged population of three french regions — The MONICA study 1995-97. Diabetes Metab, 2001, 27, 347-58. 23. Harris MI. Diabetes in America: epidemiology and scope of the problem. Diabetes Care, 1998, 21, C11-C14. Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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24. Kenny SJ, Aubert RE, Geiss LS. Prevalence and incidence of noninsulin-dependent diabetes. In: National diabetes data group. Diabetes in America. Bethesda: National Institutes of Health, 1995, 47-67. 25. Eurodiab ACE study group. Variation and trends in incidence of chilhood diabetes in Europe. Lancet, 2000, 355, 873-6. 26. Detournay B, Fagnani F, Pribil C, Eschwègue E. Consommation de soins et de biens médicaux des diabétiques de type 2 en France en 1998. Diabetes Metab, 2000, 26, 225-31. 27. Brown JB, Nichols GA, Glauber HS, Bakst AW. Type 2 diabetes: incremental medical care cost during the first 8 years after diagnosis. Diabetes Care, 1999, 22, 1116-24. 28. Selby JV, Ray GT, Zhang D, Colby CJ. Excess cost of medical care for patients with diabetes in a managed care population. Diabetes Care, 1997, 20, 1396-402. 29. Coster S, Gulliford MC, Seed PT, et al. Self monitoring in type 2 diabetes mellitus: a meta-analysis. Diabet Med, 2000, 17, 755-61. 30. Haut comité de la santé publique. Ministère de l’Emploi et de la Solidarité. Rapport du groupe de travail Diabètes. Prévention, dispositif de soins et éducation du patient. Paris, 1998. 31. Sourty-Le Guellec MJ. Profils de consommateurs de soins: France 1995. Paris, CREDES, 1999.
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32. Veterans Health Administration. Clinical guidelines for management of patients with diabetes mellitus. Washington (DC), VHA Headquarters, 1997. 33. American Diabetes Association. Economic consequences of diabetes mellitus in the U.S. in 1997. Diabetes Care, 1998, 21, 296-309. 34. Scheen AJ, Lefèvre PJ. Pharmaco-économie du diabète de type 2. Rev Med Liege, 1998, 53, 5, 285-9. 35. Leese B. Diabetes mellitus and the St Vincent Declaration. The economic implications. PharmacoEconomics, 1995, 7, 292-307. 36. Amato L, Paolisso G, Cacciatore F et al. Non insulin-dependent diabetes mellitus is associated with a greater prevalence of depression in the elderly. Diabetes Metab, 1996, 22, 314-8. 37. Gray A, Fenn P, McGuire A. The cost of insulin-dependent diabetes mellitus (IDDM) in England and Wales. Diabet Med, 1995, 12, 106876. 38. Ragnarson-Tennvall G, Apelqvist J. Cost effective management of diabetic foot ulcers. A review. Pharmacoeconomics, 1997, 12, 42-53. 39. O’Brien JA, Shomphe LA, Kavanagh PL, Raggio G, Caro JJ. Direct médical cost of complications resulting from type 2 diabetes in the US. Diabetes Care, 1998, 21, 1122-8.
A R T I C L E
The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000?* Ph Ricordeau, A Weill, N Vallier, R Bourrel, D Schwartz, J Guilhot, P Fender, H Allemand
S UMMARY
R Eu S U M Eu
Objectives: Our aim was to update available data concerning the prevalence and cost of diabetes in metropolitan France. Methods: We performed a retrospective study using patient reimbursement data from all the 128 local health offices (CPAM) in metropolitan France. We selected patients who received reimbursements for an oral hypoglycemic agent or insulin. Thus, 704,423 patients were studied by using 1998 data and 1,145,603 patients were studied by using data from 2000. The expenditures studied represented the total amount reimbursed by national health insurance to diabetic patients. The cost differential which could be attributed to diabetes was calculated by determining the difference between costs generated by diabetic patients to those generated by the rest of the population of the same age. Results: Between 1998 and 2000, the prevalence of diabetes treated in the population of affiliates covered by the general scheme increased from 2.78% to 2.96%. The total amount paid by the general scheme for care to diabetic patients (related to diabetes or not) was 5.710 billion euros in 2000 compared to 4.862 billion euros in 1998. The amount which can be attributed to diabetes alone can be estimated to be 2.414 billion euros in 2000 compared to 2.021 billion euros in 1998. After considering the impact of the increase in the number of treated diabetics, a modification in the modalities of medical care probably accounts for 183 million euros of the cost increase. Medical equipment (self blood glucose monitoring devices, reagent strips, finger lancets....) accounts for 39.3% (72 million euros) of this cost differential, medications account for 34.4% (63 million euros) and nursing care 16.9% (31 million euros). There was no change in the cost of diabetes with relation to expenses for medical consultations.
Prévalence et coût du diabète en France métropolitaine : quelles évolutions entre 1998 et 2000 ?
Key-words: Cost analysis z Diabetes Mellitus z France z Pharmaco-epidemiology z Prevalence. Ricordeau Ph, Weill A, Vallier N, Bourrel R, Schwartz D, Guilhot J, Fender P, Allemand H. The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000? Diabetes Metab 2003,29,497-504
Objectif : Notre objectif était de faire le point sur les données disponibles portant sur la prévalence et le coût du diabète en France métropolitaine. Méthodes : Nous avons conduit une étude rétrospective portant sur les données de remboursement des 128 CPAM de France métropolitaine. Nous avons sélectionné les patients qui ont reçu au moins un remboursement d’hypoglycémiant oral ou d’insuline. Ainsi, 704 423 patients ont été étudiés en utilisant les données de 1998, et 1 145 603 patients en utilisant les données de 2000. Les dépenses étudiées représentent le montant total remboursé par l’assurance maladie aux patients diabétiques. Le différentiel de coût qui peut être attribué au diabète a été calculé en déterminant la différence entre les coûts générés par les patients diabétiques et ceux générés par le reste de la population du même âge. Résultats : Entre 1998 et 2000, la prévalence du diabète traité dans la population relevant du régime général a augmenté de 2,78 % à 2,96 %. Le montant total des dépenses du régime général pour les soins donnés aux patients diabétiques (liés au diabète ou non) a été de 5,710 milliards d’euros en 2000 comparés à 4,862 milliards d’euros en 1998. Le montant attribuable au diabète peut être estimé à 2,414 milliards d’euros en 2000 comparés à 2,021 milliards d’euros en 1998. Après neutralisation de l’impact de l’augmentation du nombre de diabétiques traités, l’accroissement des coûts s’expliquait pour 183 millions d’euros par une modification des modalités de prise en charge des patients. Le matériel médical (appareils d’autosurveillance glycémique, bandelettes, autopiqueurs...) représente 39,3 % (72 millions d’euros) de ce différentiel de coût, les médicaments représentent 34,4 % (63 millions d’euros) et les soins infirmiers 16,9 % (31 millions d’euros). Il n’y a pas eu de variation du coût du diabète en rapport avec les honoraires médicaux. Mots-clés : Analyse de coût z Diabète sucré z France z Pharmaco-épidemiologie z Prévalence.
Address correspondence and reprint requests to: Ph Ricordeau. CNAMTS, 66, avenue du Maine, 75694 Paris Cedex 14, France. [email protected] *A French version of this article has already been published in the Revue Médicale de l’Assurance Maladie, 2002, vol. 33 Direction du Service médical de l’Assurance maladie (CNAMTS), CNAMTS, Paris, France.
Received: May 26th, 2003; accepted: June 15th, 2003 Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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U
sing the momentum of the Saint Vincent Declaration [1], the three main French healthcare funds launched a multi-annual program in public health in June 1999 aimed at improving the clinical management of type 2 diabetes mellitus. This program used national health insurance’s database [2-4] and was designed to evaluate the clinical management of diabetic patients by quantifying the reimbursements they received for care. The statistical study performed at that time also provided an estimation of the total amount of care reimbursed to patients in 1998 by the entire general healthcare scheme which covers 83.4% of the French population [5], irrespective of the type of diabetes they had: 4.862 billion euros of which 2.021 billion could be attributed to care for diabetes mellitus [6]. This public health program consisted in promoting the practice guidelines which had been published during the first trimester of 1999 by the National Agency for Accreditation and Health Evaluation (ANAES) [7] and the French Agency for the Security of Health Products (AFSSAPS) [8] to healthcare professionals. Accordingly, between June and December 1999, national health insurance’s salaried medical advisors (médecins conseils) encountered or directly contacted nearly 23,000 primary care physicians in order to present them with the guidelines. This strategy proved to be efficacious since a subsequent study, performed using an identical methodology and 1998 data, demonstrated that, in 2000, the medical management of patients had shown some improvement and that the recorded improvement was at least partially related to national healthcare’s program [9]. A remaining task was to update available data on prevalence and especially on the cost of diabetes for the year 2000 by measuring the contemporary changes in the results of the program.
Method We have already described in detail the method we used in 1998 to identify treated diabetic patients and to calculate total patient reimbursements (supplement in the September 2000 issue of Diabetes & Metabolism) [6, 10, 11]. In particular, the supplement clearly describes how data was gathered, the statistical analysis used, how results were validated, the calculation of correction coefficients and how the results were weighted. Interested readers are invited to consult the above-mentioned issue. The method used to update this data was rigorously identical to the previously described method. Here, we present a synthesis of the method and its key principles.
Data gathering By using the information contained in the computer databases of each local health office (CPAM) stored in the 498
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Table I
Oral hypoglycemic agents used in France to identify patients. Therapeutic Class Sulfonylureas
Biguanides Glinides Alphaglucosidase inhibitors
Common international designation Carbutamide, Chlorpropamide, Glibenclamide, Glibornuride, Gliclazide, Glimepiride, Glipizide, Tolbutamide Metformin Répaglidin Acarbose, Miglitol
health fund’s information system (SIAM)1, the general scheme for salaried workers has access to an important database containing all benefits reimbursed to affiliates in addition to precise information on prescribed laboratory tests and medications which are identified by specific codes. Due to the unique and exhaustive relationship between treated diabetes mellitus and the medications prescribed for this disorder, this database can be used to identify diabetics receiving treatment. Consequently, information was gathered by launching a series of identical parametric computer requests into the databases of each 128 local health offices (CPAM) in metropolitan France during the first trimester of 1999 (for 1998 data) and during the first trimester of 2001 (for 2000 data). Due to technical difficulties, information concerning the total cost of care given to patients in 1998 was only available from 110 of the 128 CPAMs. The list of oral hypoglycemic agents obtained from this selection included biguanides, sulfonylureas, alpha-glucosidase inhibitors as well as, for the year 2000, repaglidin, which was commercialized in March 2000. The list did not include adjuvants such as benfluorex (Tab I). In this study, the population source from which statistical individuals were obtained was defined by all affiliates in the general scheme for salaried workers stricto sensu (affiliates and eligible family members) who received reimbursement for at least one diabetes medication during the three-month inclusion period which was identifiable by its CIP2 code: oral hypoglycemic agents (OHA) or insulin. The general scheme stricto sensu excludes local supplemental health funds (supplemental funds covering state-employed teachers, government employees and officials, post office workers, students, etc.) which represent 16% of the population covered by the general scheme. During the validation phase, 0.9% of the statistical individuals were excluded (6,130 out of 1. The National Committee on Information and Liberty (CNIL) authorized the national health fund to add to SIAM data for precisely identifying medications and laboratory tests reimbursed to patients. 2. The CIP code (Inter Pharmaceutical Club) is a identification number corresponding to each pharmaceutical product in France.
Prevalence and cost of diabetes in France
710,553) in the calculations used to study 1998 data and 0.5% (6,107 out of 1,151,710) in the calculations used to study 2000 data. These exclusions mainly concerned statistical individuals for whom no information on age and/or sex was available (the majority of the cases involved patients who died during the inclusion period or who had changed healthcare funds). Overall, we enrolled 704,423 diabetics treated during 1998 and 1,145,603 diabetics treated during 2000.
Statistical analysis Correcting for patient enrollment and weighing of results
In the beginning of the year 2001, the pharmacy coding system was incompletely integrated into local health office computer systems: the rate was 89% over the entire national territory but the actual percentage was different in each individual CPAM. Two years earlier, the rate was 70.3%, thus explaining the difference in the number of patients enrolled in 1998 and 2000. In fact, the number of diabetics identified by the coding system month after month was proportional to the progressive increase in the integration rate; indirectly, this suggested that the population of patients selected by the pharmacy coding system was representative [11]. In order to compare the results obtained from 1998 and 2000 data, we corrected for the number of diabetics identified in the reimbursement database by comparing the rate of integration of the CIP code in each CPAM individually. In addition, for 1998 data, the average costs found in the 110 CPAM included in the study were applied to the enrolled diabetics identified in the databases of the 18 CPAMs3 for whom cost information was lacking. Finally, in order to facilitate the analysis and obtain results for the general scheme overall and not solely for the general scheme stricto sensu, even if the last-mentioned represents 84% of all affiliates, we applied the prevalence seen in this population to the total number of affiliates in the general scheme (49,208,966 individuals on December 31, 1999) [5, 12]. Calculation of the cost of care given to diabetics
The economic data used was the total amount reimbursed by the general fund during the 12-month period preceding the enrollment period, irrespective of the disorder motivating reimbursement. These expenditures only concerned the general fund’s direct costs for treating diabetes and did not include income-replacement benefits given to salaried affiliates (sick pay, annuities or pensions). Calculations were based on expenditures for all diabetics irrespective of the kind treatment they received (insulin alone, insulin combined with oral hypoglycemic agents or oral hypoglycemic agents alone). In this article, we present the 3. The CPAM of Calvados, l’Orne, la Manche, L’Eure, Elbeuf, Dieppe, Le Havre, Rouen, Côtes d’Armor, Bouches-du-Rhône, les Ardennes, la Marne, l’Aube, la HauteMarne, Longwy, Nancy, la Meuse and les Vosges.
results in aggregate form. Out-patient expenses included reimbursements for doctors’ fees (medical consultations but excluding examinations performed in public institutions), medications and laboratory tests, nursing care (injections, bandages, care to dependent persons), medical equipment (syringes, reagent strips, self blood glucose monitoring devices, finger lancets...), patient transportation (taxis, taxiambulances, ambulances...) as well as an expense category containing other out-patient expenditures (physical therapy, dental care, eyeglass care...). Hospitalization expenditures were comprised by hospitalization costs in private facilities (including doctors’ fees) as well as costs related to hospital stays in public institutions receiving an annual endowment. Statistical treatment of data consisted in calculating the average amount reimbursed to each patient, for whatever disorder, diabetes-related or not, followed by an average cost differential obtained by subtracting the average amount reimbursed to diabetic patients from the average amount reimbursed, in the same age-group, to the entire population of affiliates who received at least one reimbursement during the course of the year. Finally, by applying the average patient costs for 1998 to the number of diabetics in the general fund in 2000, we were able to estimate in the expenditure increase due to diabetes mellitus, the effects of the change in the number of diabetics treated on the one hand and, on the other hand, the changes in the medical management of these patients. Tools and statistical methods
We used SPSSt version 9.0.1 software and an IBMt Pentium III computer located in the office of the direction of the medical service of the national health fund for salaried workers (CNAMTS) for treating the anonymous data obtained. We utilized classic descriptive statistical methods including adjustments for patients’ ages. Confidence intervals are not given with the results since the study population can be considered exhaustive and does not represent a sample. We did not test the differences in the average costs for diabetes mellitus. Indeed, since the survey population was so large, any difference, even a very small one, could be significant in the statistical sense of the word without reflecting any real difference with perceptible public health consequences.
Results
Prevalence For 2000 data, the survey population contained 1,145,603 diabetic patients who were identified by using the reimbursement database of the CPAMs. After correcting for the pharmacy coding integration rate, this corresponded to a population of 1,230,851 diabetic affiliates of the general health fund stricto sensu, or a prevalence of 2.96% if all treatment modalities are considered (14.7% of treated diabetics Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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were treated with insulin alone, 5.3% with both insulin and oral hypoglycemic agents (OHA) and 80.0% OHA without any insulin). All treatment modalities combined, in 1998 the prevalence was 2.78%. 14.7% of diabetics were treated solely with insulin, 4.3% with a combination of insulin and oral hypoglycemic agents (OHA) and 81.0% OHA alone with no insulin at all [10]. Thus, between 1998 and 2000, the prevalence of treated diabetes in the population covered by the general health fund stricto sensu increased by an annual average of 3.2%. In order to calculate the health fund’s expenditures for the management of diabetes, these different prevalence rates were applied to the overall population covered by the general fund.
Health fund expenditures for delivered drug prescriptions and care given to diabetic patients In 2000, the general fund’s total expenditures for delivered drug prescriptions and care given to diabetics was 5.710 billion euros; 2.398 billion of this amount covered in-hospital care (42.0%) and 3.312 billion euros were spent on outpatient primary care (58.0%). In comparison, in 1998, total expenditures were 4.862 billion euros of which 2.164 billion euros covered in-hospital care (44.5%) and 2.698 billion euros were allocated to out-patient primary care (55.5%). Thus, over the two-year period, reimbursement to the general fund’s affiliates increased by 0.848 billion euros or an annual increase of 8.4%. 72.4% of this increase was for out-patient primary care (Tab II). The average annual increase in total expenditures per patient grew from 3,680 euros in 1998 to 3,914 euros in 2000 (an annual increase of 3.1%) or an increase of 234 euros per patient over the two-year period (Tab II).
Cost differential of diabetes for the health fund When taking into account the standardization of patient’s ages in 2000 and in 1998, diabetics cost4 the health fund an average of 1.7 times more compared to costs generated by the general population. In 2000, the health fund reimbursed an average of 1,655 euros per diabetic patient’s; 30.6% of this total (507 euros) was for in-hospital expenses and 69.4% (1,148 euros) was for care prescribed or delivered in out-patient primary care. In 1998, the health fund reimbursed an average of 1,529 euros to each diabetic patient: 32.8% of this total (502 euros) was for in-hospital expenses and 67.2% (1,027 euros) covered care prescribed or delivered in out-patient primary care (Tab III). By applying these results to the total number of diabetics identified in the general health fund, the overall cost generated by diabetics in 2000 can be estimated to be 2.414 billion 4. In this article, the cost differential is defined by the difference in health fund expenditures for total care to diabetic patient’s compared to expenditures for care to the general population (average expenditure per patient of the same age).
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Table II
Health fund expenditures for delivered prescriptions and care given to diabetic patients, for whatever disorder, in 1998 and 2000 (data for the general scheme in France). Average amount per patient (in euros) 1998 2000
Total amount (general scheme) (in billions of euros) 1998 2000
Out-patient primary care for... Doctors’ fees Medications Lab. Tests Nursing care α Med. equipment β Transportation χ Others δ
2,042
2,270
2,698
3,312
320 971 102 272 154 74 149
329 1,077 110 301 222 86 145
0,423 1,282 0,135 0,360 0,204 0,097 0,197
0,479 1,571 0,161 0,440 0,324 0,126 0,211
Hospital Stays
1,638
1,644
2,164
2,398
Total
3,680
3,914
4,862
5,710
α
Nursing care (injections, bandages, care given to dependent patients). β Medical equipment (syringes, reagent strips, self blood glucose monitoring devices....). χ Transportation (ambulance, taxi-ambulance, taxi). δ Other out-patient expenditures (physical therapy, dental care...).
euros for this population of which 1.675 billion euros were reimbursed uniquely for out-patient care and 0.739 billion euros for in-hospital expenses. Between 1998 and 2000, the health fund’s expenditures for diabetes increased by 393 million euros, or an increase of 19.4% (318 million euros for out-patient care and 75 million euros for in-hospital care) (Tab III). Of the 318 million euros spent on out-patient care, 134 million were for medications, 87 million for medical equipment, 57 million for nursing care, 13 million for laboratory tests and 13 million for doctor’s fees. Between 1998 and 2000, the cost of care to diabetics increased by 19.4%. More than half of this cost increase (10.3%) can be explained by the increase in the number of treated diabetics. After compensating for this effect, changes in the clinical management of these patients accounts for an increase of 183 million euros. An increase in expenses for medical equipment represented 39.3% (72 million euros) of this total, 34.4% (63 million euros) corresponded to expenses for medications, nursing care represented 16.9% (31 million euros) of this increase, 6.6% (12 million euros) went to patient transportation and finally, laboratory tests accounted for 2.7% (5 million euros) of the increase. The only explanation for the variation in the cost of doctors’ fees for diabetes between 1998 and 2000 was the increase in the number of treated patients.
Prevalence and cost of diabetes in France
Table III
Average cost differential per patient and total cost differential for the healthcare fund for diabetic patients treated in 1998 and 2000 (data from the general scheme in France). Average amount per patient (in euros) 1998 2000
Total amount (general scheme) (in billions of euros) 1998 2000
Out-patient primary care for... Doctors’ fees Medications Lab. Tests Nursing care α Med. equipment β Transportation χ Others δ Hospital Stays
1,027
1,148
1,357
1,675
95 527 57 187 113 27 21 502
95 570 60 209 162 35 17 507
0,125 0,697 0,075 0,248 0,149 0,035 0,028 0,664
0,138 0,831 0,088 0,305 0,236 0,051 0,026 0,739
Total
1,529
1,655
2,021
2,414
α
Nursing care (injections, bandages, care given to dependent patients). β Medical equipment (syringes, reagent strips, self blood glucose monitoring devices....). χ Transportation (ambulance, taxi-ambulance, taxi). δ Other out-patient expenditures (physical therapy, dental care...).
Discussion
The contributions of the survey A higher prevalence of diabetes mellitus in the French population
The prevalence of diabetes mellitus in the population of affiliates covered by the general health insurance fund increased an average of 3.2% per year between 1998 and 2000. For a start, this regular increase in prevalence, already predicted by epidemiologists, can be explained by demographic changes similar to those observed in other western countries: aging of the population, increase in longevity and the arrival, in the age-group carrying a high risk for diabetes, of the children born during the “baby-boom” [13]. Part of the prevalence increase can undoubtedly also be attributed to improved screening for the disease and sociological factors associated with life-style changes, particularly an augmentation in obesity and a general decrease in physical activity [14-16]. For these reasons, the World Health Organization (WHO) predicts a 35% increase in the worldwide prevalence of diabetes over the next few years [17]. Lowering of the diagnostic threshold between 1998 and 2000 [18, 19] from 1.40 g/L (7.8mmol/L) to 1.26 g/L (7.0mmol/L) may have also played a part in the prevalence increase even though, up until the present, numerous studies have concluded that a lowering of the diagnostic criteria should not appreciably modify the overall prevalence of diabetes mellitus [13, 20,
21]. On the other hand, the population survey performed in France between 1995 and 1997 in the three MONICA centers which gathered information on a number of laboratory test results, concluded that a reduction in the diagnostic criteria for fasting blood sugar could result in an important increase (X 2.2) in the number of diabetics identified in the 35 to 64 year-old age group [22]. The increase in prevalence of diabetes mellitus is not confined to France. Other studies, mostly performed in the United States [23, 24] show similar results with respect to both type 1 diabetes mellitus, whose incidence is increasing in wealthy countries [25], and type 2 diabetes mellitus. Thus, the number of patients in the United States with type 2 diabetes has already increased by 35% between 1993 and 1998 [23, 24]. The prevalence of diabetes in metropolitan France at the beginning of 2001 (2.96% in the population of affiliates covered by the general health insurance fund stricto sensu) is intermediate between the countries in Northern Europe, whose prevalence was estimated at 2.4% in the middle of the 1990s and who represent 90% of the total number of patients [13, 14], and the Mediterranean countries (Italy, Greece, Spain and Portugal) who have recorded a prevalence in excess of 4.0% [8]. The health fund’s expenditures for drug prescriptions and care delivered to diabetics in 2000
The general health fund reimbursed, all diseases combined, an average of 3,914 euros per patient in 2000; 1,655 euros of that amount was spent on the overall management of diabetes mellitus and its complications. This amount exceeds the estimate (3,064 euros) published in France in the multi-center European study known as CODE-2 [26]. In addition to the fact that CODE-2 studied reimbursements to patients in 1998, a number of other factors can explain the differences found between those results and our findings. In a previous publication, we have already discussed these factors: different patient recruitment (for example, only patients with type 2 diabetes were enrolled in the CODE-2 study), differences in the method used for information gathering and differences in the categories of expenses considered (the CODE-2 study excluded costs for patient transportation and for medical materials) [6]. If our results are compared to those found in other countries-mostly concerning the United States-expenditures in France appear to be lower even if comparisons of this kind are difficult due to important differences in the organization of care and disease management. Be that as it may, Brown et al. [27] followed 30,377 type 2 diabetics for from 1 to 8 years and found that, during the first eight years following the diagnosis, their care cost an average of $ 2,257 per year (in 1993 dollars) more than care to paired subjects. Elsewhere, Selby et al. [28] calculated the cost differential ($ 3,494 in 1994 dollars per patient per year) between diabetics and non-diabetics in a representative sample of the American population. These cost differentials Diabetes Metab 2003,29,497-504 • © 2003 Masson, all rights reserved
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($ 2,257 for Brown et al. and $ 3,494 for Selby et al.) are greater than the cost differential found in our study (1,655 euros). The changes in expenditures between 1998 and 2000
First of all, the change in expenditures can be explained by the rapid increase in the number of treated diabetics, already mentioned above. Over two years, an additional 72 million euros were spent on prescriptions for medical equipment (including, notably, self blood glucose monitoring devices and reagent strips) even though present data suggest that self blood glucose monitoring does not help reduce glycated hemoglobin levels [29]. With our data, we were unable to identify the therapeutic drug classes mainly responsible for the 63 million euro increase in drug prescriptions. In the CODE-2 study, cardiovascular and lipid-lowering drugs represented the most significant part of the increase in expenditures for medications [26] and it is all together possible that prescriptions for these same medications played an important role in the increase in expenditures we found. Moreover, between 1998 and 2000, the percentage of patients receiving lipid-lowering drugs grew from 38.0% to 40.3% [9].
Limits and validity of our results Selection of diabetics by using the pharmacy coding system
This study was based on patient reimbursements during a fixed time period. By definition, the general health fund only has access to information concerning medications for which its affiliates have requested reimbursement. Some drug prescriptions may have never been filled if the patient already had a sufficient supply at home to meet his needs. However, by enrolling patients reimbursed during a threemonth period for this chronic disorder which generally requires monthly prescription pharmacy renewal, we can probably assume that the patient population receiving at least one prescription over the three-month period corresponds to the overall population of treated diabetics. On the other hand, the health fund’s information system is totally incapable of identifying patients whose diabetes is sufficiently controlled by life-style measures alone, a cohort which the High Committee on Public Health estimated at 10% of type 2 diabetics in 1998 [30] and, in addition, offers no information a fortiori on undiagnosed diabetics, whose numbers remain unknown. Even if, on the average, these patients utilize much less care than other diabetics, we still must consider the fact that our results fail to take into account their expenditures. If we consider the integration parameters of the pharmacy coding system into the health fund database, our results probably do not contain any selection bias related to incomplete integration of the coding system. Indeed, in addition to the large number of diabetics identified by the coding system (70.3% of all medications were coded in 1998 and 89.0% were coded in 2000), the progressive, almost propor502
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tional increase in the diabetic population compared to the integration rate of the coding system [11], strongly suggests that, for most local health agencies, the selected population was representative. Accordingly, there is no reason to believe that the costs generated by the diabetics who were excluded from our computer survey were different from those identified by the coding system. Determining the cost of diabetes mellitus
In determining total expenditures for diabetics, the health fund included amounts paid to facilities financed by global budgeting for hospital stays related to diabetes. However, part of these hospital stays are incompletely reported since some healthcare facilities file late and/or incomplete reports on individual patients, thereby depriving local health agencies (CPAM) of the necessary information. The magnitude of the unreported information is impossible to measure but this fact definitely results in an underestimation of the total cost for diabetes management. In addition, in calculating the cost differential due to diabetics, rigorous methodology would have required deducting data on the diabetic population from data on the overall population covered by the general scheme. Unfortunately, this in not possible with a computer database survey. Even if we take that fact into account, the bias introduced is undoubtedly minimal since diabetes has an estimated prevalence of 3% in the population covered by the general scheme. However, the calculation method we used introduced a more important bias, leading us to underestimate the cost differential attributed to diabetes due to the fact that we do not know the number of affiliates covered by the general scheme according to age-group and we based average costs on the amounts reimbursed solely to the cohort of patients who requested at least one reimbursement during the year (termed the population of “consumers”). But it just so happens that a study performed by the CREDES in 1995 found that 9.7% of the covered population does not utilize any healthcare resources during a given year [31]. Even if this “non-consumer” population only represents a slight percentage in the age-groups containing the highest prevalence for diabetes (3.6% between 65 and 79 years and 0.9% beyond that age), in our study, the average costs based on the reference population we used are definitely a little overestimated and, consequently, the cost differentials attributed to diabetes are somewhat underestimated. The choice of the method used
We limited our study to expenditures for affiliates of the general healthcare fund. In order to determine total reimbursements to all patients, it would have been necessary to include reimbursements in the other healthcare funds (mainly covering the agricultural profession, craftsmen and merchants) which cover 16.6% of the French population. The general fund’s database stored in local health agencies only records reimbursed benefits to patients and contains no clinical information or laboratory test results. Thus,
Prevalence and cost of diabetes in France
it is impossible to deduce the relative numbers of patients with type 1 and type 2 diabetes mellitus from the information available to the general health fund since, at the present time, essentially clinical criteria are used to differentiate the two forms [32]. It appears that an important proportion of authentic type 2 diabetics (estimated to be 50% by most authors) are treated with insulin in addition to oral hypoglycemic agents or sometimes with insulin alone; moreover, they often have the most severe forms of type 2 diabetes. Accordingly, it is probably not very relevant to differentiate the three therapeutic modes in order to perform a medicoeconomic study (in general, insulin-treated diabetics are the most expensive). The European CODE-2 study confirmed this notion: it found that insulin-treated diabetics utilized two times the direct health resources as diabetics treated solely with oral hypoglycemic agents (OHA) [26]. Our study was limited exclusively to the direct costs of diabetes mellitus and excluded indirect costs generated by income replacement benefits, disability pensions and premature mortality. In a 1997 American Diabetes Association study which enrolled an elderly and mostly professionally inactive population, indirect costs for diabetes were found to be greater than direct costs [33]. A comprehensive determination of the total cost of diabetes mellitus would also require taking into account parameters like the quality of life, which are difficult to measure: psychological, familial and social consequences [34, 35]. In witness, a study found that depression was more prevalent in a cohort of patients with type 2 diabetes than in a control group [36]. Finally, this study was not able to differentiate costs solely related to the clinical follow-up of diabetes mellitus (blood sugar control, screening for complications) from those attributed to its degenerative complications since local health office data provides no clinical information or laboratory test results. It just so happens that a number of studies addressing diabetes have shown that overall management costs are mostly due to the treatment of complications [25, 37-39]. In addition, the European CODE-2 study found that direct medical costs are multiplied by a factor of 2 when macrovascular complications are present and by a factor of 3.5 when both micro and macrovascular complications coexist [26].
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