- Email: [email protected]
Medication-related factors affecting health care outcomes and costs for patients with psoriasis in the United States
Medication-related factors affecting health care outcomes and costs for patients with psoriasis in the United States Amit S. Kulkarni, MS,a Rajesh Balkrishnan, PhD,a,b,c David Richmond, MA,c Daniel J. Pearce, MD,b and Steven R. Feldman, MD, PhDb,c Houston, Texas, and Winston-Salem, North Carolina Background: The impact of psoriasis medication therapy on costs and patient outcomes in large nationally representative samples needs further examination. Objective: This study examined the association between factors related to medication use, health status, and health care costs associated with psoriasis in the United States. Methods: A cross-sectional cohort study was performed using the 2000 Medical Expenditure Panel Survey database. Information on health care service use, health status (EuroQol-5D instrument), and patient demographics were obtained from the database representing approximately 1.1 million patients with psoriasis. EuroQol was used in the Medical Expenditure Panel Survey. Results: Weighted multiple linear regression analysis indicated that use of topical corticosteroid therapy was associated with a decrease in psoriasis-specific health care costs (53.2% lower than average costs vs patients using no medications, P = .022) and better health status (34.0% higher than average scores vs patients using no medications, P = .006). Conclusions: We observed an association with topical corticosteroids for treatment of psoriasis on health care outcomes and costs. ( J Am Acad Dermatol 2005;52:27-31.)
soriasis is a common skin disease1 with approximately 1 in every 50 US citizens having it.2 The treatment of psoriasis costs as much as $1.6 to $3.2 billion annually in the United States2-7 and, depending on the severity of the disease, annual outpatient cost of psoriasis ranges between $1400 and $6600 per patient.3,8,9 A large portion of this is
P
From the Division of Management, Policy, and Community Health, University of Texas Health Science Center at Houston, School of Public Healtha; and Center for Dermatology Researchb and Department of Public Health Sciences,c Wake Forest University School of Medicine, Winston-Salem, North Carolina. This study was conducted in conjunction with the Center for Dermatology Research, Wake Forest University School of Medicine, which is supported by a grant from Galderma Inc. No other funding was obtained for the study. Conflicts of interest: None identified. Accepted for publication August 3, 2004. Reprint requests: Rajesh Balkrishnan, PhD, University of Texas Schools of Public Health and Medicine, RAS-E331, 1200 Herman Pressler, Houston, TX 77030. E-mail: Rajesh.Balkrishnan@ uth.tmc.edu. 0190-9622/$30.00 ª 2005 by the American Academy of Dermatology, Inc. doi:10.1016/j.jaad.2004.08.004
toward controller medications used to help reduce the incidence of acute attacks and keep psoriasis under control.10 Although there are several therapeutic strategies available for the treatment of psoriasis,11-13 topical corticosteroids appear to be the mainstay of psoriasis treatment.8,14-17 Of physicians, 85% indicate topical corticosteroids as their first choice.14 Treatments for psoriasis presently available provide temporary symptomatic relief aimed at inducing and maintaining remission.1,9 Thus, patients with psoriasis have a constant cost associated with their treatment owing to its chronic and recurring nature. Psoriasis has a tremendous impact on the quality of life of patients.1,18 Patients with psoriasis also experience stigmatization, especially if lesions are on body areas that are normally exposed or that are required to be exposed during the course of daily duties.1,19 Because of the recurrent nature and the stigma associated with psoriasis, depressive symptomatolgy is common for patients with psoriasis.20-23 The purpose of this study was to examine the association between factors related to medication 27
28 Kulkarni et al
use, health status, and health care costs associated with the treatment of psoriasis in the United States.
METHODS Sample and measurement This was a cross-sectional cohort study. The Medical Expenditure Panel Survey (MEPS) dataset was analyzed for this study. MEPS is a national survey of noninstitutionalized US civilians. The MEPS dataset quantifies insurance costs and out-of-pocket spending for all medical services. Each MEPS is a sample population from the previous year’s National Health Interview Survey respondents. The 2000 MEPS dataset was analyzed for this study. The MEPS collects self-reported health status data using the EuroQol (EQ-5D) instrument for all adults aged 18 years or more. Hence, analysis for health status was carried out for all adults aged 18 years or more. MEPS also includes data on the sociodemographic characteristics of respondents and self-reported medical conditions, defined on the basis of the first 3 digits of the International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification codes. The patients for this study were identified using ICD9 code 696 for psoriasis vulgaris and similar conditions (MEPS dataset uses only the first 3 digits of the ICD-9 codes to identify disease state). Records of medical events for each patient were obtained using this ICD-9 code for psoriasis and the receipt of medication for psoriasis as identified by a dermatologist as outlined below. These records included information on office-based medical provider and outpatient visits. Each medical event was collapsed to one record for each patient with psoriasis containing the number of visits, total amount paid, number of visits for psoriasis, and total amount paid for psoriasis visits. This information was used in obtaining psoriasis-related health care costs. For prescribed medicines, a dermatologist identified medications for psoriasis and for severe psoriasis. Data regarding the different types and forms of prescribed psoriasis medications used by the patients were obtained from the MEPS dataset. For the purpose of analysis, the study population was divided into categories depending on type of medications they were using: topical corticosteroids; other medications; combination therapy; systemic medication; and no pharmacologic agents. Information regarding self-reported health status of the patients was retrieved from the EQ-5D scores in the MEPS dataset. Demographic information of the patients was also retrieved from the MEPS dataset. Patients using UVB therapy, photochemotherapy, methotrexate, acitretin, and cyclosporine were classified as having severe psoriasis.
J AM ACAD DERMATOL JANUARY 2005
Next, a comorbidity index was developed based on the approach of Charlson et al.24 This index has been validated for several other health outcome estimations besides death and has been adapted for use with ICD-9 codes.25 The index assigns weights for a number of major conditions (range 1-6). The index severity score is calculated for each patient by totaling the assigned weight for each of the patient’s comorbidities. An additional index was created to measure the total number of prescription refills.26 Statistical analysis Data for approximately 1.1 million patients (weighted sample size) with psoriasis in the 2000 MEPS dataset was analyzed. All analyses were weighted using the MEPS sampling weights. The unit of analysis for all analyses was the individual patient. First, bivariate statistics were used (1-way analysis of variance) to compare all potential predictors of health care costs and health status. Significant confounders from the bivariate analyses that were correlated with either study outcomes were included in the weighted multiple linear regression models examining the impact of type of pharmacotherapy (topical corticosteroids, others, or none) on health care costs and health status.27 All analyses were conducted using software (Release 5.0, STATA, College Station, Tex).
RESULTS A majority of the population was aged between 26 and 49 years (42.5%). Of patients, 38.6% were being treated with topical corticosteroids, 7.0% with other medications, and 35.8% were not using any pharmacotherapy. Demographic information of the study population is outlined in Table I. The average comorbidity burden in the population was minor, as evidenced by the comorbidity severity index of Charlson et al (mean = 1.20).24 The annual psoriasisrelated health care costs were approximately $460 with $227 spent on psoriasis-specific drugs. Patients on some type of pharmacotherapy had nearly $259 increased annual psoriasis-related health care costs and 28.5% higher EQ-5D scores compared with patients not using pharmacotherapy. The multivariate models examining predictors of health status (EQ-5D summary score) explained around 26% of the variance. The study population using topical corticosteroids had better health status (34.0% improvement in EQ-5D summary scores among users vs nonusers, P = .006). The study population with private insurance had better health status than those with public health insurance (P \.01).
Kulkarni et al 29
J AM ACAD DERMATOL VOLUME 52, NUMBER 1
Multivariate analysis examining predictors of psoriasis-related health care costs explained around 78% of the variance. Among medication-related factors, use of topical corticosteroid therapy was associated with lower psoriasis-specific health care costs (53.2% lower costs than the average among users vs nonusers, P = .022). The use of other medications was not associated with any significant reduction in costs or improvements in health status compared with patients receiving no pharmacologic treatment. Increased psoriasis prescription refill rates were associated with an increase in psoriasis-specific health care costs (P \ .01). More information on the variables included in these models is shown in Table II.
DISCUSSION This study exemplifies the fact that topical corticosteroids are the mainstay in psoriasis treatment with almost 39% of patients receiving these medications. This is a positive outlook to the problems associated with psoriasis, especially in light of the favorable findings for topical corticosteroids from this study. This study has found two strong associations that are of great interest. It is seen that use of controller medications, most notably topical corticosteroids, is possibly the primary driver of reduced health care costs and improved health status for patients with psoriasis. The reduction in health care costs may be associated with the availability of topical corticosteroids in inexpensive generic forms. There seems to be a differential beneficial impact of topical corticosteroids compared with other medications for treatment of psoriasis on health care outcomes and costs. Topical corticosteroids, one of the treatment options mentioned in the American Academy of Dermatology consensus statement on psoriasis therapies,13 are the most highly prescribed topical drugs.28 However, studies have shown two major concerns related to the use of topical corticosteroids. First, dermatologists concerned with side effects associated with topical corticosteroid therapy have limited their use, especially outside the United States.28 Efforts have been made in devising new medication regimens to prevent these side effects,29 which might help encourage dermatologists to prescribe topical corticosteroids. The second issue of concern, especially to patients at large, is the cosmetic appeal of topical corticosteroids, with patients preferring nonmessy medications.30 It has been seen that the vehicles used to deliver topical therapy affect efficacy and also play an important role in medication adherence.30 A study
Table I. Descriptive statistics of study population (n = 1.1 million [weighted sample]) Variable
Age, y 0-17 (%) 18-25 (%) 26-49 (%) 50-64 years (%) $65 (%) Male sex (%) Sample with severe psoriasis (%) Sample with private insurance Charlson et al24 comorbidity index score Medications Topical corticosteroids (%) Other medicines (%) Combination therapy (%) No pharmacologic agents (%) Sample with severe psoriasis (%) Psoriasis-specific annual drug refills Psoriasis-specific annual office-based visits by study population EuroQol self-reported health status summary score (out of 100) Psoriasis-specific annual health care costs ($)
Mean (Std*)
9.7 4.6 42.5 28.2 15.0 43.3 3.3 79.08 1.20 (6 0.81)
38.56 7.03 18.59 35.82 3.3 3.76 (6 0.67) 2.74 (6 0.64) 59.08 (6 3.37) 460.75 (6 53.64)
*Presented where applicable.
has shown stress to be associated with patients with psoriasis, particularly because of their anticipation of reactions from other people.31 This has a tremendous effect on the quality of life of the patients. This may accentuate the need for nonmessy topical corticosteroid preparations. The pharmaceutic industry has devised new vehicles that are cosmetically more elegant, clinically more efficient, and are well accepted by the patients.30
CONCLUSION The findings of this study pertaining to topical corticosteroids and their possible association with decreased psoriasis-related health care spending and increased quality of life should encourage providers and payers alike. Controller medication use is an important cornerstone of successful psoriasis management. Moreover, the availability of topical corticosteroids in inexpensive generic forms, with regimens that decrease side effects and in cosmetically preferred form, should encourage physicians, patients, and payers toward increased adoption of controller medications to improve patient outcomes and decrease patient costs.
30 Kulkarni et al
J AM ACAD DERMATOL JANUARY 2005
Table II. Results of multivariate analysis for predictors of psoriasis-specific health care costs and health status Dependent variables ) Independent variables+
Health status (EuroQol self-reported health status summary score, R2 = 0.26)
Male sex Private insurance Age 0-17 y Age $65 y Comorbidities Psoriasis-specific drug refills Severity of psoriasis Corticosteroid therapyz Other medication usez Combination therapyz No. psoriasis-specific office-based visits Intercept
4.41 (6.15) 18.24 (6.32)y e 16.14 (10.19) 4.18 (2.54) 1.34 (0.76) 6.69 (15.39) 17.95 (6.27)y 14.80 (11.86) 0.54 (14.50) 0.39 (0.32) 75.37 (8.59)y
Psoriasis-specific annual health care costs (R2 = 0.78)
83.42 (58.24) 68.71 (49.23) 77.11 (50.12) 101.10 (58.78) 9.62 (36.05) 53.33 (15.82)y 315.45 (213.49) 147.56 (60.96)* 230.28 (164.86) 110.06 (214.63) 81.32 (27.42)y 27.16 (61.42)
ß coefficients are presented with SE indicates in parentheses. *P \ .05. y P \ .01. z Reference (dropped) category is patients using no pharmacotherapy for psoriasis.
Limitations The study focused only on direct health care costs related to medical care. Respondent bias and underreporting of actual health care service use, because of reliance on self-report and potential recall bias, cannot be ruled out. There is a small potential of miscoding of clinical diagnosis of psoriasis during the coding of the survey or during the actual data entry process. Use of over-the-counter medications or some other type of nonprescription medicationrelated therapy (such as UV treatments) were not captured by the MEPS database. The study sample was interviewed in the prebiologics era, and the study findings may be a little different in contrast to present times. However, these minor limitations do not diminish the tremendous implications of this study’s findings for dermatologic practice and treatment policy. Finally, there is also a possibility that less severe (hence, less costly) psoriasis leads to steroids as the treatment choice, as opposed to treatment with steroids leading to decreased costs. Health status is a complex construct requiring many variables to completely explain it in a regression model. Some of these are not captured by secondary databases like MEPS, a shortcoming of using such databases. A low R2 value, however, does not belittle the underlying significance of the analysis, which remains intact. Previous studies carried out using these databases have shown a low R2 value associated with studies of this nature.26,32 To our knowledge, this is the first attempt at assessing costs and health status associated with psoriasis using a nationally representative database such as the MEPS. The study population, hence, is highly representative of the US population, which
strengthens the generalizability of this study. As previous studies have been carried out in an academic or hospital setting, these patients had more a more severe form of psoriasis than seen in the general population. Hence, there is a distinct possibility that costs in the overall population are lower than those projected from previous estimates. REFERENCES 1. Vardy D, Besser A, Amir M, Gesthalter B, Biton A, Buskila D. Experiences of stigmatization play a role in mediating the impact of disease severity on quality of life in psoriasis patients. Br J Dermatol 2002;147:736-42. 2. Rapp SR, Feldman SR, Exum ML, Fleischer AB Jr, Reboussin DM. Psoriasis causes as much disability as other major medical diseases. J Am Acad Dermatol 1999;41:401-7. 3. Finzi AF, Mantovani LG, Belisari A. Italian Association for Studies on Psoriasis. The cost of hospital-related care of patients with psoriasis in Italy based on the AISP study. J Eur Acad Dermatol Venereol 2001;15:320-4. 4. Jenner N, Campbell J, Plunkett A, Marks R. Cost of psoriasis: a study on the morbidity and financial effects of having psoriasis in Australia. Australas J Dermatol 2002;45:255-61. 5. National Psoriasis Foundation. Psoriasis: treatment options and patient management. National Psoriasis Foundation. http://www.psoriasis.org/facts/psoriasis/Viewed on 7/26/04. 6. Feldman SR, Fleischer AB Jr, Reboussin DM, Rapp SR, Bradham DD, Exum ML, et al. The economic impact of psoriasis increases with psoriasis severity. J Am Acad Dermatol 1997;37:564-9. 7. Choi J, Koo JYM. Quality of life issues in psoriasis. J Am Acad Dermatol 2003;49(Suppl):S57-61. 8. Galadari I, Rigel E, Lebwohl M. The cost of psoriasis treatment. J Eur Acad Dermatol Venereol 2001;15:290-1. 9. Marchetti A, LaPensee K, An P. A pharmacoeconomic analysis of topical therapies for patients with mild to moderate stable plaque psoriasis: a US study. Clin Ther 1998;20:851-69. 10. Stuart B, Singhal PK, Magder LS, Zuckerman IH. How robust are health plan quality indicators to data loss? A Monte Carlo simulation study of pediatric asthma treatment. Health Serv Res 2003;38:1547-61.
J AM ACAD DERMATOL VOLUME 52, NUMBER 1
11. Lebwohl M, Ali S. Treatment of psoriasis. Part 1: topical therapy and phototherapy. J Am Acad Dermatol 2001;45: 487-98. 12. Ashcroft DM, Po LW, Griffith CEM. Therapeutic strategies for psoriasis. J Clin Pharm Ther 2000;25:1-10. 13. Callen JP, Krueger GG, Lebwohl M, McBurney EI, Mease P, Menter A, et al. AAD consensus statement on psoriasis therapies. J Am Acad Dermatol 2003;49:897-9. 14. Linden KG, Weinstein GD. Psoriasis: current perspectives with an emphasis on treatment. Am J Med 1999;107:595-605. 15. Al-Suwaidan SN, Feldman SR. Clearance is not a realistic expectation of psoriasis treatment. J Am Acad Dermatol 2002;42:796-802. 16. Baughman RD. A 61-year-old man with psoriasis. JAMA 1996; 276:1421-8. 17. Koo J, Lebwohl M. Duration of remission of psoriasis therapies. J Am Acad Dermatol 1999;41:51-9. 18. Feldman SR, Garton R, Averett W, Balkrishnan R, Vallee J. Strategy to manage the treatment of severe psoriasis: consideration of efficacy, safety and cost. Expert Opin Pharmacother 2003;4:1525-33. 19. Richards HL, Fortune DG, Main CJ, Griffiths CE. Stigmatization and psoriasis. Br J Dermatol 2003;149:209-10. 20. Devrimci-Ozguven H, Kundakci TN, Kumbasar H, Boyvat A. The depression, anxiety, life satisfaction and affective expression levels in psoriasis patients. J Eur Acad Dermatol Venereol 2000; 14:267-71. 21. Akay A, Pekcanlar A, Bozdag KE, Altintas L, Karaman A. Assessment of depression in subjects with psoriasis vulgaris and lichen planus. J Eur Acad Dermatol Venerol 2002;16:347-52. 22. Sharma N, Koranne RV, Singh RK. Psychiatric morbidity in psoriasis and vitiligo: a comparative study. J Dermatol 2001;28: 419-23.
Kulkarni et al 31
23. Mattoo SK, Handa S, Kaur I, Gupta N, Malhotra R. Psychiatric morbidity in vitilgo and psoriasis: a comparative study from India. J Dermatol 2001;28:424-32. 24. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chron Dis 1987;27:387-404. 25. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613-9. 26. Balkrishnan R, Rajagopalan R, Camacho FT, Huston SA, Murray FT, Anderson RT. Predictors of medication adherence and associated health care costs in an older population with type 2 diabetes mellitus: a longitudinal cohort study. Clin Ther 2003; 25:2958-71. 27. Greene WH. Econometric analysis. 3rd ed. Englewood Cliffs (NJ): Prentice Hall; 1997. 28. Van de Kerkhof PC, Steegers-Theunissen RP, Kuipers MV. Evaluation of topical drug treatment in psoriasis. Dermatology 1998;197:31-6. 29. Katz HI, Prawer SE, Medansky RS, Krueger GG, Mooney JJ, Jones ML, et al. Intermittent corticosteroid maintenance treatment of psoriasis: a double blind multi center trial of augmented betamethasone dipropionate ointment in a pulse dose treatment regimen. Dermatologica 1991;183:269-74. 30. Feldman SR, Housman TS. Patients’ vehicle preference for corticosteroid treatments of scalp psoriasis. Am J Clin Dermatol 2003;4:221-4. 31. Lebwohl M, Ali S. Treatment of psoriasis. Part 2: systemic therapies. J Am Acad of Dermatol 2001;45:649-61. 32. Balkrishnan R, Christensen DB. Inhaled corticosteroid use and associated outcomes in elderly patients with moderate to severe chronic pulmonary disease. Clin Ther 2000;22: 452-69.
soriasis is a common skin disease1 with approximately 1 in every 50 US citizens having it.2 The treatment of psoriasis costs as much as $1.6 to $3.2 billion annually in the United States2-7 and, depending on the severity of the disease, annual outpatient cost of psoriasis ranges between $1400 and $6600 per patient.3,8,9 A large portion of this is
P
From the Division of Management, Policy, and Community Health, University of Texas Health Science Center at Houston, School of Public Healtha; and Center for Dermatology Researchb and Department of Public Health Sciences,c Wake Forest University School of Medicine, Winston-Salem, North Carolina. This study was conducted in conjunction with the Center for Dermatology Research, Wake Forest University School of Medicine, which is supported by a grant from Galderma Inc. No other funding was obtained for the study. Conflicts of interest: None identified. Accepted for publication August 3, 2004. Reprint requests: Rajesh Balkrishnan, PhD, University of Texas Schools of Public Health and Medicine, RAS-E331, 1200 Herman Pressler, Houston, TX 77030. E-mail: Rajesh.Balkrishnan@ uth.tmc.edu. 0190-9622/$30.00 ª 2005 by the American Academy of Dermatology, Inc. doi:10.1016/j.jaad.2004.08.004
toward controller medications used to help reduce the incidence of acute attacks and keep psoriasis under control.10 Although there are several therapeutic strategies available for the treatment of psoriasis,11-13 topical corticosteroids appear to be the mainstay of psoriasis treatment.8,14-17 Of physicians, 85% indicate topical corticosteroids as their first choice.14 Treatments for psoriasis presently available provide temporary symptomatic relief aimed at inducing and maintaining remission.1,9 Thus, patients with psoriasis have a constant cost associated with their treatment owing to its chronic and recurring nature. Psoriasis has a tremendous impact on the quality of life of patients.1,18 Patients with psoriasis also experience stigmatization, especially if lesions are on body areas that are normally exposed or that are required to be exposed during the course of daily duties.1,19 Because of the recurrent nature and the stigma associated with psoriasis, depressive symptomatolgy is common for patients with psoriasis.20-23 The purpose of this study was to examine the association between factors related to medication 27
28 Kulkarni et al
use, health status, and health care costs associated with the treatment of psoriasis in the United States.
METHODS Sample and measurement This was a cross-sectional cohort study. The Medical Expenditure Panel Survey (MEPS) dataset was analyzed for this study. MEPS is a national survey of noninstitutionalized US civilians. The MEPS dataset quantifies insurance costs and out-of-pocket spending for all medical services. Each MEPS is a sample population from the previous year’s National Health Interview Survey respondents. The 2000 MEPS dataset was analyzed for this study. The MEPS collects self-reported health status data using the EuroQol (EQ-5D) instrument for all adults aged 18 years or more. Hence, analysis for health status was carried out for all adults aged 18 years or more. MEPS also includes data on the sociodemographic characteristics of respondents and self-reported medical conditions, defined on the basis of the first 3 digits of the International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification codes. The patients for this study were identified using ICD9 code 696 for psoriasis vulgaris and similar conditions (MEPS dataset uses only the first 3 digits of the ICD-9 codes to identify disease state). Records of medical events for each patient were obtained using this ICD-9 code for psoriasis and the receipt of medication for psoriasis as identified by a dermatologist as outlined below. These records included information on office-based medical provider and outpatient visits. Each medical event was collapsed to one record for each patient with psoriasis containing the number of visits, total amount paid, number of visits for psoriasis, and total amount paid for psoriasis visits. This information was used in obtaining psoriasis-related health care costs. For prescribed medicines, a dermatologist identified medications for psoriasis and for severe psoriasis. Data regarding the different types and forms of prescribed psoriasis medications used by the patients were obtained from the MEPS dataset. For the purpose of analysis, the study population was divided into categories depending on type of medications they were using: topical corticosteroids; other medications; combination therapy; systemic medication; and no pharmacologic agents. Information regarding self-reported health status of the patients was retrieved from the EQ-5D scores in the MEPS dataset. Demographic information of the patients was also retrieved from the MEPS dataset. Patients using UVB therapy, photochemotherapy, methotrexate, acitretin, and cyclosporine were classified as having severe psoriasis.
J AM ACAD DERMATOL JANUARY 2005
Next, a comorbidity index was developed based on the approach of Charlson et al.24 This index has been validated for several other health outcome estimations besides death and has been adapted for use with ICD-9 codes.25 The index assigns weights for a number of major conditions (range 1-6). The index severity score is calculated for each patient by totaling the assigned weight for each of the patient’s comorbidities. An additional index was created to measure the total number of prescription refills.26 Statistical analysis Data for approximately 1.1 million patients (weighted sample size) with psoriasis in the 2000 MEPS dataset was analyzed. All analyses were weighted using the MEPS sampling weights. The unit of analysis for all analyses was the individual patient. First, bivariate statistics were used (1-way analysis of variance) to compare all potential predictors of health care costs and health status. Significant confounders from the bivariate analyses that were correlated with either study outcomes were included in the weighted multiple linear regression models examining the impact of type of pharmacotherapy (topical corticosteroids, others, or none) on health care costs and health status.27 All analyses were conducted using software (Release 5.0, STATA, College Station, Tex).
RESULTS A majority of the population was aged between 26 and 49 years (42.5%). Of patients, 38.6% were being treated with topical corticosteroids, 7.0% with other medications, and 35.8% were not using any pharmacotherapy. Demographic information of the study population is outlined in Table I. The average comorbidity burden in the population was minor, as evidenced by the comorbidity severity index of Charlson et al (mean = 1.20).24 The annual psoriasisrelated health care costs were approximately $460 with $227 spent on psoriasis-specific drugs. Patients on some type of pharmacotherapy had nearly $259 increased annual psoriasis-related health care costs and 28.5% higher EQ-5D scores compared with patients not using pharmacotherapy. The multivariate models examining predictors of health status (EQ-5D summary score) explained around 26% of the variance. The study population using topical corticosteroids had better health status (34.0% improvement in EQ-5D summary scores among users vs nonusers, P = .006). The study population with private insurance had better health status than those with public health insurance (P \.01).
Kulkarni et al 29
J AM ACAD DERMATOL VOLUME 52, NUMBER 1
Multivariate analysis examining predictors of psoriasis-related health care costs explained around 78% of the variance. Among medication-related factors, use of topical corticosteroid therapy was associated with lower psoriasis-specific health care costs (53.2% lower costs than the average among users vs nonusers, P = .022). The use of other medications was not associated with any significant reduction in costs or improvements in health status compared with patients receiving no pharmacologic treatment. Increased psoriasis prescription refill rates were associated with an increase in psoriasis-specific health care costs (P \ .01). More information on the variables included in these models is shown in Table II.
DISCUSSION This study exemplifies the fact that topical corticosteroids are the mainstay in psoriasis treatment with almost 39% of patients receiving these medications. This is a positive outlook to the problems associated with psoriasis, especially in light of the favorable findings for topical corticosteroids from this study. This study has found two strong associations that are of great interest. It is seen that use of controller medications, most notably topical corticosteroids, is possibly the primary driver of reduced health care costs and improved health status for patients with psoriasis. The reduction in health care costs may be associated with the availability of topical corticosteroids in inexpensive generic forms. There seems to be a differential beneficial impact of topical corticosteroids compared with other medications for treatment of psoriasis on health care outcomes and costs. Topical corticosteroids, one of the treatment options mentioned in the American Academy of Dermatology consensus statement on psoriasis therapies,13 are the most highly prescribed topical drugs.28 However, studies have shown two major concerns related to the use of topical corticosteroids. First, dermatologists concerned with side effects associated with topical corticosteroid therapy have limited their use, especially outside the United States.28 Efforts have been made in devising new medication regimens to prevent these side effects,29 which might help encourage dermatologists to prescribe topical corticosteroids. The second issue of concern, especially to patients at large, is the cosmetic appeal of topical corticosteroids, with patients preferring nonmessy medications.30 It has been seen that the vehicles used to deliver topical therapy affect efficacy and also play an important role in medication adherence.30 A study
Table I. Descriptive statistics of study population (n = 1.1 million [weighted sample]) Variable
Age, y 0-17 (%) 18-25 (%) 26-49 (%) 50-64 years (%) $65 (%) Male sex (%) Sample with severe psoriasis (%) Sample with private insurance Charlson et al24 comorbidity index score Medications Topical corticosteroids (%) Other medicines (%) Combination therapy (%) No pharmacologic agents (%) Sample with severe psoriasis (%) Psoriasis-specific annual drug refills Psoriasis-specific annual office-based visits by study population EuroQol self-reported health status summary score (out of 100) Psoriasis-specific annual health care costs ($)
Mean (Std*)
9.7 4.6 42.5 28.2 15.0 43.3 3.3 79.08 1.20 (6 0.81)
38.56 7.03 18.59 35.82 3.3 3.76 (6 0.67) 2.74 (6 0.64) 59.08 (6 3.37) 460.75 (6 53.64)
*Presented where applicable.
has shown stress to be associated with patients with psoriasis, particularly because of their anticipation of reactions from other people.31 This has a tremendous effect on the quality of life of the patients. This may accentuate the need for nonmessy topical corticosteroid preparations. The pharmaceutic industry has devised new vehicles that are cosmetically more elegant, clinically more efficient, and are well accepted by the patients.30
CONCLUSION The findings of this study pertaining to topical corticosteroids and their possible association with decreased psoriasis-related health care spending and increased quality of life should encourage providers and payers alike. Controller medication use is an important cornerstone of successful psoriasis management. Moreover, the availability of topical corticosteroids in inexpensive generic forms, with regimens that decrease side effects and in cosmetically preferred form, should encourage physicians, patients, and payers toward increased adoption of controller medications to improve patient outcomes and decrease patient costs.
30 Kulkarni et al
J AM ACAD DERMATOL JANUARY 2005
Table II. Results of multivariate analysis for predictors of psoriasis-specific health care costs and health status Dependent variables ) Independent variables+
Health status (EuroQol self-reported health status summary score, R2 = 0.26)
Male sex Private insurance Age 0-17 y Age $65 y Comorbidities Psoriasis-specific drug refills Severity of psoriasis Corticosteroid therapyz Other medication usez Combination therapyz No. psoriasis-specific office-based visits Intercept
4.41 (6.15) 18.24 (6.32)y e 16.14 (10.19) 4.18 (2.54) 1.34 (0.76) 6.69 (15.39) 17.95 (6.27)y 14.80 (11.86) 0.54 (14.50) 0.39 (0.32) 75.37 (8.59)y
Psoriasis-specific annual health care costs (R2 = 0.78)
83.42 (58.24) 68.71 (49.23) 77.11 (50.12) 101.10 (58.78) 9.62 (36.05) 53.33 (15.82)y 315.45 (213.49) 147.56 (60.96)* 230.28 (164.86) 110.06 (214.63) 81.32 (27.42)y 27.16 (61.42)
ß coefficients are presented with SE indicates in parentheses. *P \ .05. y P \ .01. z Reference (dropped) category is patients using no pharmacotherapy for psoriasis.
Limitations The study focused only on direct health care costs related to medical care. Respondent bias and underreporting of actual health care service use, because of reliance on self-report and potential recall bias, cannot be ruled out. There is a small potential of miscoding of clinical diagnosis of psoriasis during the coding of the survey or during the actual data entry process. Use of over-the-counter medications or some other type of nonprescription medicationrelated therapy (such as UV treatments) were not captured by the MEPS database. The study sample was interviewed in the prebiologics era, and the study findings may be a little different in contrast to present times. However, these minor limitations do not diminish the tremendous implications of this study’s findings for dermatologic practice and treatment policy. Finally, there is also a possibility that less severe (hence, less costly) psoriasis leads to steroids as the treatment choice, as opposed to treatment with steroids leading to decreased costs. Health status is a complex construct requiring many variables to completely explain it in a regression model. Some of these are not captured by secondary databases like MEPS, a shortcoming of using such databases. A low R2 value, however, does not belittle the underlying significance of the analysis, which remains intact. Previous studies carried out using these databases have shown a low R2 value associated with studies of this nature.26,32 To our knowledge, this is the first attempt at assessing costs and health status associated with psoriasis using a nationally representative database such as the MEPS. The study population, hence, is highly representative of the US population, which
strengthens the generalizability of this study. As previous studies have been carried out in an academic or hospital setting, these patients had more a more severe form of psoriasis than seen in the general population. Hence, there is a distinct possibility that costs in the overall population are lower than those projected from previous estimates. REFERENCES 1. Vardy D, Besser A, Amir M, Gesthalter B, Biton A, Buskila D. Experiences of stigmatization play a role in mediating the impact of disease severity on quality of life in psoriasis patients. Br J Dermatol 2002;147:736-42. 2. Rapp SR, Feldman SR, Exum ML, Fleischer AB Jr, Reboussin DM. Psoriasis causes as much disability as other major medical diseases. J Am Acad Dermatol 1999;41:401-7. 3. Finzi AF, Mantovani LG, Belisari A. Italian Association for Studies on Psoriasis. The cost of hospital-related care of patients with psoriasis in Italy based on the AISP study. J Eur Acad Dermatol Venereol 2001;15:320-4. 4. Jenner N, Campbell J, Plunkett A, Marks R. Cost of psoriasis: a study on the morbidity and financial effects of having psoriasis in Australia. Australas J Dermatol 2002;45:255-61. 5. National Psoriasis Foundation. Psoriasis: treatment options and patient management. National Psoriasis Foundation. http://www.psoriasis.org/facts/psoriasis/Viewed on 7/26/04. 6. Feldman SR, Fleischer AB Jr, Reboussin DM, Rapp SR, Bradham DD, Exum ML, et al. The economic impact of psoriasis increases with psoriasis severity. J Am Acad Dermatol 1997;37:564-9. 7. Choi J, Koo JYM. Quality of life issues in psoriasis. J Am Acad Dermatol 2003;49(Suppl):S57-61. 8. Galadari I, Rigel E, Lebwohl M. The cost of psoriasis treatment. J Eur Acad Dermatol Venereol 2001;15:290-1. 9. Marchetti A, LaPensee K, An P. A pharmacoeconomic analysis of topical therapies for patients with mild to moderate stable plaque psoriasis: a US study. Clin Ther 1998;20:851-69. 10. Stuart B, Singhal PK, Magder LS, Zuckerman IH. How robust are health plan quality indicators to data loss? A Monte Carlo simulation study of pediatric asthma treatment. Health Serv Res 2003;38:1547-61.
J AM ACAD DERMATOL VOLUME 52, NUMBER 1
11. Lebwohl M, Ali S. Treatment of psoriasis. Part 1: topical therapy and phototherapy. J Am Acad Dermatol 2001;45: 487-98. 12. Ashcroft DM, Po LW, Griffith CEM. Therapeutic strategies for psoriasis. J Clin Pharm Ther 2000;25:1-10. 13. Callen JP, Krueger GG, Lebwohl M, McBurney EI, Mease P, Menter A, et al. AAD consensus statement on psoriasis therapies. J Am Acad Dermatol 2003;49:897-9. 14. Linden KG, Weinstein GD. Psoriasis: current perspectives with an emphasis on treatment. Am J Med 1999;107:595-605. 15. Al-Suwaidan SN, Feldman SR. Clearance is not a realistic expectation of psoriasis treatment. J Am Acad Dermatol 2002;42:796-802. 16. Baughman RD. A 61-year-old man with psoriasis. JAMA 1996; 276:1421-8. 17. Koo J, Lebwohl M. Duration of remission of psoriasis therapies. J Am Acad Dermatol 1999;41:51-9. 18. Feldman SR, Garton R, Averett W, Balkrishnan R, Vallee J. Strategy to manage the treatment of severe psoriasis: consideration of efficacy, safety and cost. Expert Opin Pharmacother 2003;4:1525-33. 19. Richards HL, Fortune DG, Main CJ, Griffiths CE. Stigmatization and psoriasis. Br J Dermatol 2003;149:209-10. 20. Devrimci-Ozguven H, Kundakci TN, Kumbasar H, Boyvat A. The depression, anxiety, life satisfaction and affective expression levels in psoriasis patients. J Eur Acad Dermatol Venereol 2000; 14:267-71. 21. Akay A, Pekcanlar A, Bozdag KE, Altintas L, Karaman A. Assessment of depression in subjects with psoriasis vulgaris and lichen planus. J Eur Acad Dermatol Venerol 2002;16:347-52. 22. Sharma N, Koranne RV, Singh RK. Psychiatric morbidity in psoriasis and vitiligo: a comparative study. J Dermatol 2001;28: 419-23.
Kulkarni et al 31
23. Mattoo SK, Handa S, Kaur I, Gupta N, Malhotra R. Psychiatric morbidity in vitilgo and psoriasis: a comparative study from India. J Dermatol 2001;28:424-32. 24. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chron Dis 1987;27:387-404. 25. Deyo RA, Cherkin DC, Ciol MA. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613-9. 26. Balkrishnan R, Rajagopalan R, Camacho FT, Huston SA, Murray FT, Anderson RT. Predictors of medication adherence and associated health care costs in an older population with type 2 diabetes mellitus: a longitudinal cohort study. Clin Ther 2003; 25:2958-71. 27. Greene WH. Econometric analysis. 3rd ed. Englewood Cliffs (NJ): Prentice Hall; 1997. 28. Van de Kerkhof PC, Steegers-Theunissen RP, Kuipers MV. Evaluation of topical drug treatment in psoriasis. Dermatology 1998;197:31-6. 29. Katz HI, Prawer SE, Medansky RS, Krueger GG, Mooney JJ, Jones ML, et al. Intermittent corticosteroid maintenance treatment of psoriasis: a double blind multi center trial of augmented betamethasone dipropionate ointment in a pulse dose treatment regimen. Dermatologica 1991;183:269-74. 30. Feldman SR, Housman TS. Patients’ vehicle preference for corticosteroid treatments of scalp psoriasis. Am J Clin Dermatol 2003;4:221-4. 31. Lebwohl M, Ali S. Treatment of psoriasis. Part 2: systemic therapies. J Am Acad of Dermatol 2001;45:649-61. 32. Balkrishnan R, Christensen DB. Inhaled corticosteroid use and associated outcomes in elderly patients with moderate to severe chronic pulmonary disease. Clin Ther 2000;22: 452-69.