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Cost of informal care for diabetic patients in Thailand
p r i m a r y c a r e d i a b e t e s 5 ( 2 0 1 1 ) 109–115
Contents lists available at ScienceDirect
Primary Care Diabetes journal homepage: http://www.elsevier.com/locate/pcd
Original research
Cost of informal care for diabetic patients in Thailand Susmita Chatterjee a , Arthorn Riewpaiboon a,∗ , Piyanuch Piyauthakit b , Wachara Riewpaiboon c a
Division of Social and Administrative Pharmacy, Department of Pharmacy, Faculty of Pharmacy, Mahidol University, 447, Sri Ayutthaya Road, Bangkok 10400, Thailand b Waritchaphum Hospital, 83 Moo 13 Waritchaphum sub-district, Waritchaphum District, Sakhon Nakhon 47150, Thailand c Health promotion program for people with disability, Health System Research Institute, Ministry of Public Health, Tivanond Road, Nonthaburi 11000, Thailand
a r t i c l e
i n f o
a b s t r a c t
Article history:
Aims: The study estimated the cost of informal care for 475 randomly selected diabetic
Received 3 August 2010
patients as identified by International Classification of Diseases, tenth revision (ICD-10
Received in revised form
codes = E10–E14) and who received treatment at Waritchaphum hospital in Sakhon Nakhon
11 November 2010
province of Thailand during the financial year 2008.
Accepted 22 January 2011
Methods: Informal care was valued by using revealed preference method. Information of
Available online 18 February 2011
informal caregiving was collected through direct personal interview method either from
Keywords:
by using recall method.
the patients or from the caregivers. The data on time spent for informal care were collected Cost
Results: The study covered a total of 190 informal caregivers. Average time spent on informal
Informal care
care was 112.38 h per month. The estimated cost of informal care was USD 110,713.08 using
Diabetes
opportunity cost approach and USD 93,896.52 using proxy good method in 2008 (1 USD = 32
Revealed preference method
Thai Baht).
Caregivers
Conclusions: The study concluded that the hidden cost associated with informal caregiving is
Thailand
a burden for the Thai society. Hence, the economic cost associated with informal caregiving should be considered for future analyses of both the public health consequences of diabetes and interventions aimed at decreasing diabetic complications. © 2011 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.
1.
Introduction
Diabetes is a common chronic disease with increasing burdens in Thailand [1]. The national prevalence of diabetes in Thai adults aged ≥35 years was estimated 9.6% in 2000 and 6.7% among people aged ≥15 years in 2004 [2,3]. The high prevalence of diabetes leads to an increase in preva-
∗
lence of diabetic complications. The chronic nature of the disease and its devastating complications make it a very costly disease. In Thailand there exist some studies which tried to estimate the cost of diabetes, however, these studies focused either on provider or patient perspective, hence, one cost component namely the cost of informal care had never been evaluated [4–6]. Even in other countries, where societal perspective was used to estimate cost of diabetes, this cost
Corresponding author. Tel.: +66 2644 8678 91x5745; fax: +66 2644 8694. E-mail addresses: s chatterjee [email protected] (S. Chatterjee), [email protected] (A. Riewpaiboon), [email protected] (P. Piyauthakit), [email protected] (W. Riewpaiboon). 1751-9918/$ – see front matter © 2011 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.pcd.2011.01.004
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component was ignored [7,8]. The only study that evaluated cost of informal care for elderly individuals with diabetes in the US found that the cost was between USD 3 and 6 billion per year, similar to the estimates of the annual paid long term care cost attributable to diabetes [9]. This emphasized the importance of valuing the hidden cost related to informal care in cost of illness analysis following societal perspective. Cost calculations and economic evaluations excluding informal care might suggest interventions to be cost saving or cost effective, but this result might be simply because of the exclusion of cost of informal care from the analysis [10,11]. ‘Informal care’ is the name given to the care provided by people from a care recipient’s social network: family, friends, acquaintances or neighbors [12]. Schulz and Beach reported that providing informal care can be stressful and may increase informal caregivers’ morbidity and mortality risks [13]. Hence, in economic terms, the evidence for informal caregivers’ increased morbidity and mortality risks due to providing informal care implies that informal care is not free when viewed over the medium and long term. Even in the short term, the provision of informal care is not free, at the very least it entails opportunity cost in terms of foregone paid work, unpaid work and leisure [14–18]. Hence, determining the cost of informal care is important in formulating health policy, because it reveals society’s opportunity costs of caring for people with various diseases and what could be saved by eradicating them [19]. Though relatively little research had focused specifically on informal caregiving for diabetes [9,20], a significant literature exist regarding the economic effects of informal caregiving for dementia and stroke [21–26]. Most studies had found that the cost associated with unpaid informal caregiver time account for a majority of the total cost of the disease. Given this backdrop, the objective of the present study was to estimate the cost of informal care for the diabetic patients at a public district hospital in Thailand.
2.
Methods
2.1.
Study site and study population
The study was conducted at Waritchaphum hospital, a public district hospital in Waritchaphum district of Sakhon Nakhon province in Thailand. As the present study was the first study which estimated cost of informal care for diabetic patients in Thailand, hence, there was no sufficient background information to calculate a formal sample size for this study. Based on available resources [27] and sample size used in one informal care study in Thailand [26], for this study the sample size was fixed at 475. A total of 1415 diabetic patients (inpatients and outpatients taken together) received treatment from the study hospital in 2008. Assuming non-availability and refusal rate of 15%, 546 patients were randomly selected from the electronic diabetic patient database of the study hospital and were targeted to be sequentially contacted for this study. The study team stopped contacting patients as soon as complete data were available from 475 diabetic patients (the pre-determined sample size for this study). When contacted for interview,
five patients were not available and three refused to be interviewed. Information of informal caregiving was collected through direct personal interview method either from the patients or from the caregivers. The caregivers were approached when the patients were not sure about the activities of their informal caregivers. A structured pre-tested questionnaire was administered to obtain those information. The data collection was done by a team of trained health centre and hospital staff of Waritchaphum district during January and March 2009. The study got ethical clearance from the Institutional Review Board of Mahidol University, Bangkok, Thailand. Written informed consent was obtained from all respondents who participated in this study.
2.2.
Conceptual framework of informal care
There are several methods for measurement of time of informal care. The most important methods are the diary, considered the gold standard, and the recall method [11]. In diary method, respondents are asked to write down all their activities during a specific period of time. This method has an important disadvantage as it requires a lot of time and effort from the respondents and is also very costly for the researchers. Therefore this method cannot be used in all situations. A less demanding method like recall method is then preferred, even though a major concern with this retrospective way of questioning is its reliability because of recall bias [11]. Given this disadvantage, for convenience, in this study the data on time spent for informal care were collected by using recall method. The recall period was 1 month prior from the date of interview. In this study, it was hypothesized that the informal care was needed for activities of daily living (ADL), household activities of daily living (HDL) and instrumental activities of daily living (IADL). These concepts were followed from Van den Berg et al. [28]. For treating diabetes and its complications, a number of medications are required. Further, as the disease becomes severe, the medical regimen becomes complex. Hence, the diabetic patients need help for managing medications, glucose monitoring, foot care, etc. To capture these, an additional activity namely health care activities (HCA) was added. Informal caregivers were asked how many minutes per day they spent on all the activities taken together mentioned under HCA. The ADL include personal care, moving around in the house, going to the toilet, bathing, dressing, eating and drinking, etc. Here also they were asked how many minutes they spent per day on all the activities taken together mentioned under ADL. The HDL includes preparation of food and drinks, cleaning the house, dishes, washing, ironing, sewing, etc. For the activities under HDL, informal caregivers were asked how many hours per day they spent on all these activities taken together. IADL include making trips and visiting family or friends, health care contacts, going to the bank, etc. The time spent on all the activities taken together under IADL was measured in hours per month. While asking these questions, it was made clear that only the additional part of housework due to the disease of the care recipient should be counted as informal care.
p r i m a r y c a r e d i a b e t e s 5 ( 2 0 1 1 ) 109–115
111
Total respondent N=475
Informal Caregiver (Yes) n=142
Informal Caregiver (No) n=333
One Caregiver (n=104)
Two Caregivers (n=28)
Three Caregivers (n=10)
Number of caregivers 104x1=104
Number of caregivers 28x2=56
Number of caregivers 10x3=30
Total Number of Caregivers = 190
Fig. 1 – Distribution of informal caregivers (N = 190).
2.3.
Valuation methods for informal care
The major problem in valuing informal care is that by definition no market prices exist [10]. It is often argued that informal care should be valued with the opportunity cost method [18,29,30]. The opportunity costs of informal care are the informal caregivers’ benefits foregone due to spending time on providing informal care. In opportunity cost approach, time can be valued in two ways viz. productivity cost approach and time cost approach. The productivity cost approach covers time of caregivers who still work while time cost approach covers the time spent by all caregivers. An alternative, proxy good method, is also proposed [30]. This method values time spent on informal care at the labour market price of a close market substitute. The opportunity cost method and proxy good method are termed as revealed preference method. Informal care can be valued by stated preference method as well like contingent valuation method and conjoint valuation method [31,32]. However, opportunity costs and proxy good methods are most advocated and most often used. One important reason for recommendations to use either one of these methods may be their relatively straightforward application [28]. Hence, in this study, informal care was valued by using revealed preference method. While valuing informal care by opportunity cost approach, time-cost approach was followed and minimum official wage rate of Sakhon Nakhon province, USD 4.63 per day (1 USD = 32 Thai Baht) was used as the base case [33]. As majority of the informal caregivers were either agriculturists or labourers, they did not have regular income. Further, some of them might had earned more than the minimum official wage while some others earned less than that, hence, in order to average out the differences in earning power of the informal caregivers, minimum wage rate was used. For valuing informal care using proxy good method, earnings (defined as wage plus other monetary and non-monetary benefits such as bonus, overtime, meal, etc.) from household work and from health and social work in 2003 were used. Nominal wages for 2008 (the study year) were calculated using 2003 wages and the consumer price index. According to the Labour Protection Act B.E. 2541, working time per week cannot exceed 48 h. Based on this, a total working time per month of 192 h was used to calculate the hourly wage rate. Earnings from health and social work USD 3.03 per day for Sakhon Nakhon were used for both HCA and ADL while earning from household
work USD 4.47 per day for Sakhon Nakhon was used for both HDL and IADL [34]. A sensitivity analysis examines the effect on the study results of systematic changes in key assumptions or parameters. In order to capture how the assumption of use of minimum wage rate of Sakhon Nakhon province affected the cost of informal care in opportunity cost method, sensitivity analysis was conducted by using minimum wage rate for the country as a whole. In proxy good method, one-way sensitivity analysis was performed by using the earnings for the country as a whole from the respective work, i.e. USD 4.78 per day for household work and USD 5.16 per day for health and social work.
3.
Results
3.1. Characteristics of the informal caregivers and the care recipients Among 475 study participants, 142 (29.9%) reported that they had informal caregivers. One hundred and four (21.89%) study participants had one informal caregiver, 28 (5.89%) had two informal caregivers and 10 (2.10%) participants had three caregivers. Thus the present study covered a total of 190 informal caregivers. The distribution is presented in Fig. 1. The mean ± standard deviation (SD) age of the informal caregivers was 45.28 (±16.65) years with maximum and minimum age 79 years and 9 years, respectively (Table 1). Females were relatively more engaged in informal caregiving as compared to their male counterparts (52.6% vs. 47.4%), although differences were small. Most of the informal caregivers had primary education (65.3%) and were engaged in farming (52.6%). Sons/daughters of the patients commonly served as informal caregiver (40.5%), however, spouses were also significantly engaged in informal caregiving (35.3%). Most of the informal caregivers were married (76.3%) and shared the same houses with the care recipients (87.4%). While looking at the characteristics of the care recipients, it was found that they had higher mean age as compared to those who did not need informal caregivers (p = 0.001) (Table 2). Group comparisons were done by unpaired t test and statistical significance was declared when p value was less than 0.05. The presence of complications and disability (as measured by
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Table 1 – Characteristics of informal caregivers (N = 190). Characteristics Age Less than 25 years 25–34 years 35–44 years 45–54 years 55–64 years 65 years and above Gender Male Female Marital status Single Married Divorced/widow Education Primary education Secondary education Diploma Bachelor degree Occupation Housewife Agriculturist Labour Student Govt. officials Retired person Others Relation with the patient Parents Spouse Children In-laws Brother/sister Grand children Others Living arrangements Same house with the patient Others Transport for those staying outside Walk Motorcycle Others
Number
Percentage
22 30 41 32 41 24
11.58 15.79 21.58 16.84 21.58 12.63
90 100
47.40 52.60
34 145 11
17.90 76.30 5.80
124 49 2 15
65.30 25.80 1.10 7.90
8 100 38 13 13 14 4
4.20 52.60 20.00 6.80 6.80 7.40 2.10
4 67 77 16 7 15 4
2.10 35.30 40.50 8.40 3.70 7.90 2.10
166 24
87.40 12.60
12 8 4
50.00 33.33 16.67
3.2. care
Time foregone and monetary value of informal
The informal caregivers spent maximum time in performing HDL (Table 3). Their mean (±SD) time spent on HDL was 42.21 (±39.94) hours per month, followed by IADL (mean ± SD = 9.28 ± 25.90), ADL (mean ± SD = 6.79 ± 15.45) and HCA (mean ± SD = 5.80 ± 10.13). As regards mean monetary value of informal caregiving, as per opportunity cost approach the same was USD 37.17 per month while as per proxy good method it was USD 33.54 per month. To analyze robustness of results, sensitivity analysis was conducted. In case of opportunity cost approach, country minimum wage rate was used for sensitivity analysis and for proxy good method country average earnings from household work and from health and social work were considered. The recalculation results showed that for opportunity cost approach, the mean cost increased by 7% while for proxy good method, the same increased by 16%.
4.
using Barthel index score) was significantly higher among the care recipients as compared to their counterparts [35]. Further, the care recipients had higher hospitalization rate and they visited more frequently to the provincial hospital.
Discussion
The demographic characteristics of the study sample were similar to those of all diabetic patients received treatment from the study hospital during the study period. For example, mean age and percentage of female patients in all diabetic patients at the study hospital were 59.77 years and 73% respectively while the same for the study sample was 59.34 years and 74.5%, respectively. As regards disease characteristics of the study participants, the mean duration of the disease was 7.20 years, most of the patients had type 2 diabetes (99%) and the mean fasting blood sugar level was 156.06 mg/dl. All these results are also comparable with other diabetic studies in Thailand. For example, Nitiyanant et al., Riewpaiboon et al. and Chaikledkaew et al. found 94.7%, 94%, 96% and 99% type 2 diabetic patients respectively in their studies in Thailand [1,6,36,37]. Nitiyanant et al. noted average disease duration 6.2 and 8.7 years respectively and fasting blood sugar level 167.27 and 150.91 mg/dl respectively among the diabetic patients in Thailand [1,36]. The characteristics of the informal caregivers in the present study were quite similar to those found in a recent study on informal care of disabled stroke survivors in Thailand [26]. The mean age of the informal caregivers in the present study was 45 years while the same for the other study was 46 years. Both studies found that the females were relatively more engaged in informal caregiving. This was probably because of typical
Table 2 – Characteristics of the care recipients. Characteristics
Caregiver Yes
Duration of the disease (mean ± SD) Age (mean ± SD) Fasting blood sugar level (mean ± SD) Presence of co-morbidity (%) Presence of complications (%) Presence of disability (%) Rate of hospitalization (%) Visit to provincial hospital (%)
8.28 ± 6.34 62.22 ± 12.31 158.32 ± 42.21 68.31 47.89 29.58 24.65 14.08
P value No 6.74 ± 6.38 58.13 ± 10.78 155.13 ± 35.31 63.36 24.02 6.61 6.91 6.01
0.160 0.001 0.435 0.296 0.000 0.000 0.000 0.013
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Table 3 – Time foregone and monetary value of informal care (N = 190). Time spent on (hours per month)
Mean
HCA ADL HDL IADL
5.80 6.79 42.21 9.28
SD
Median
10.13 15.45 39.94 25.90
0.00 0.00 30.00 2.00
Cost per month (USD)
Mean
Median
Inter-quartile range
Opportunity cost method Proxy good method Sensitivity – opportunity cost method Sensitivity – proxy good method
37.17 33.54 39.80 38.89
26.77 22.63 28.67 28.15
9.28–52.20 6.53–50.29 9.94–55.90 10.24–53.78
HCA = health care activities, e.g. taking medicines; ADL = activities of daily living, e.g. eating and dressing; HDL = household activities of daily living, e.g. shopping and preparing food; IADL = instrumental activities of daily living, e.g. visit to the clinic and relatives.
Thai family culture where females are primarily responsible for household tasks, including providing care to all family members including sick or disabled persons. However, several other studies conducted in different parts of the world also noticed that the females actually provided more informal care than males. Further, sons/daughters of the patients commonly served as informal caregivers followed by the spouses. This finding was also similar with the study in Thailand as well as studies in other countries [15,21,26,38]. As diabetes is a chronic illness and generally has an onset in mid life and reveal complications and consequently disability in the late life, sons/daughters or spouses were found mostly serving as informal caregivers instead of parents who usually serve as informal caregivers in case of life-long disability. While looking at the informal caregivers’ time spent on different activities, it was found that maximum time was spent for HDL. This finding was consistent with Van den Berg et al. where time spent by the informal caregivers was calculated for stroke and rheumatoid arthritis patients in The Netherlands but contradicted the finding of a recent stroke study in Thailand where it was found that most caregivers performed ADL tasks followed by HDL tasks [28,39]. Even though diabetes, stroke and rheumatoid arthritis all are chronic illnesses but stroke is an acute condition with immediate acute mobility disability while both diabetes and rheumatoid arthritis are slowly progressive chronic disease with slow progression of disability. Because of the progressive onset of disability among the diabetic patients, probably they mostly needed help for HDL tasks followed by IADL. As per the Thai culture, the sick or elderly persons are generally taken care of by their family members and there are several cases where the patients cannot access the rehabilitation services for improving their functional capacity to perform even the ADL. This is probably another reason for the caregivers performed more ADL tasks in case of disabled stroke survivors in Thailand. Another possible reason of longer time spent on HDL activities by the informal caregivers of diabetic patients could be that “normal” HDL tasks were not fully separated from additional HDL task. This reason was mentioned by Van den Berg et al. as well [28]. There exist some studies which incorporated HDL tasks mentioned in this study under IADL [40,41]. If these two types are clubbed in the present study, the informal caregivers were found to spend on average 51.5 h per month on the new broad IADL category.
The cost of informal care was calculated by using both opportunity cost and proxy good method. Several studies had shown that the opportunity cost method yielded lower results than the proxy good method [21,25]. However, contrary to those studies, in the present study the cost of informal care was lower in case of proxy good method (USD 6372 per month) as compared to opportunity cost method (USD 7062 per month). This was because those studies calculated only the cost of informal caregivers’ leisure time foregone and therefore, opportunity cost was valued at one-third of the average wage or minimum wage rate. However, in the present study, no differentiation was made between foregone paid, unpaid and leisure work, hence, all these foregone activities were valued equally by using official average minimum wage of Sakhon Nakhon province. Further, the earnings from health and social work (USD 3.03 per day) and from household work (USD 4.47 per day) which were used to calculate cost as per proxy good method were lower than the minimum average wage used to calculate cost as per opportunity cost method (USD 4.63 per day). Hence, the cost obtained using proxy good method was lower than the same obtained from opportunity cost approach. Apart from the economic burden, there is growing evidence that informal care has adverse effects on informal caregivers in terms of quality of life [13]. Further, providing informal care affects labour market participation [14]. In the present study, most of the caregivers (about 54%) were in the most productive age group of 25–54 years. The average time spent on informal care was 112.38 h per month. This might have some impact on labour market participation in the Thai society. On the other hand, increased labour market participation would reduce the supply of informal care, which in turn, would force some care recipients to accept institutionalized care instead of being cared for at home which would be more costly from a health care budget perspective. Another point to note here is that among 142 study participants who reported to have informal caregivers, 35 (about 25%) were hospitalized during the study period. The average cost of informal care (using opportunity cost approach) for the hospitalized patients was USD 79.87 as compared to USD 60.10 (p = 0.17) for the non-hospitalized patients. Hence, while allocating funds for health care, the policy makers should use the information on cost of informal care as well as other factors related to informal care. An increased attention for informal care is also important as the
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demand for informal care is likely to increase in future due to the aging of the Thai population. The following potential limitations of the present study merit comment. First, the time spent for informal care was recorded by using recall method while the diary method is considered as gold standard. However, given the disadvantages attached with diary method such as it requires a lot of time and effort from the respondents and the cost involves in applying this method, a less demanding method, i.e. the recall method is preferred. Second, it was found that the informal caregivers spent maximum time on HDL and that time was significantly higher than times spent for all other activities. One possible reason of such finding could be that “normal” HDL tasks were not fully separated from additional HDL task. However, in this study no attempts were made to compare HDL performed by general population and the study caregivers. Even though during the survey it was mentioned repeatedly that only the additional part of housework due to the disease of the care recipient should be counted as informal care, but still it may be difficult for respondents, especially in cases where informal care has been provided many years already, to distinguish between normal tasks and informal care. Hence, the estimates presented in this study particularly related to HDL might be a bit overestimated. Third, due to lack of necessary data, this study was unable to assess whether informal care was associated with significant negative health effects among caregivers. Future research should focus on whether such negative health effects occur and if so, whether these are unique aspects of diabetes caregiving. Such research would help guide potential caregiver interventions aimed at reducing the negative health outcomes of the caregivers. The present study concluded that the hidden cost associated with informal caregiving is a burden for the Thai society. A recent study estimated cost of diabetes from societal perspective in Thailand and found that the cost of informal care was the highest individual cost component in total cost of illness of diabetes (about 28%) and for that the contribution of direct non-medical cost was the highest in total cost of diabetes (about 40%) while the contributions of direct medical cost and indirect cost were 23% and 37%, respectively [42]. Hence, the policy makers should consider the economic cost associated with informal caregiving for future analyses of both the public health consequences of diabetes and interventions aimed at decreasing diabetic complications. However, to strengthen this argument a large-scale study to estimate cost of informal care among the diabetic patients in Thailand should be conducted as the present study reported the estimates for 475 diabetic patients in a public district hospital in Thailand.
Conflict of interest statement No conflicts of interest have been declared.
Acknowledgements The present study was a part of the research project under the fellowship program “Asia Fellows Awards 2008–09 (Cohort 10)” of the first author. The fellowship program was administered
by the Asian Scholarship Foundation, Bangkok, Thailand and funded by the Ford Foundation. We express our gratitude to the Asian Scholarship Foundation, Bangkok, Thailand for providing the opportunity of conducting the research. We are grateful to the National Research Council of Thailand for giving permission of conducting the present study in Thailand. We thank Faculty of Pharmacy, Mahidol University, Bangkok, for being the host institute of the research project. Special thanks go to the professors and students of Division of Social and Administrative Pharmacy, Department of Pharmacy, Mahidol University for their help and support at various stages of this research. Finally, we are indebted to all staff of Waritchaphum hospital and health centres for their support and co-operation during data collection.
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L.B. Russell, M.C. Weinstien (Eds.), Cost-Effectiveness in Health and Medicine, Oxford University Press, New York, 1996, pp. 176–213. B. Van den Berg, H. Bleichrodt, L. Eeckhoudt, The economic value of informal care: a study of informal caregivers’ and patients’ willingness to pay and willingness to accept for informal care, Health Econ. 14 (2005) 363–376. B. Van den Berg, W.B. Brouwer, N.J. Van Exel, M.A. Koopmanschap, Economic valuation of informal care: the conjoint measurement method applied to informal caregiving, Soc. Sci. Med. 61 (2005) 1342–1355. Ministry of Labour, Minimum Wage, Ministry of Labour, Bangkok, 2008. Planning and Information Group, Labour Standard Development Bureau Analysis of wages, earnings and working hours 2003 (in Thai language), Department of Labour Protection and Welfare, Ministry of Labour, Bangkok, Thailand, 2004. F. Mahoney, D. Barthel, Functional evaluation: the Barthel Index, Md. State Med. J. 14 (1965) 56–61. W. Nitiyanant, S. Chandraprasert, G. Puavilai, S. Tandhanand, A survey study on diabetes management in Thailand, J. Asean Fed. Endocr. Soc. 19 (2001) 35–41. U. Chaikledkaew, P. Pongchareonsuk, N. Chaiyakunapruk, Factors affecting health-care costs and hospitalizations among diabetic patients in Thai public hospitals, Value Health 11 (2008) S69–74. P. Jullamate, Z. de Azeredo, C. Paul, R. Subgranon, Thai stroke patient caregivers: who they are and what they need, Cerebrovasc. Dis. 21 (2006) 128–133. K. Ponsoongnern, Cost of informal care for disabled stroke survivors in Bangkok and Buriram province, Master Degree Thesis, Mahidol University, Thailand, 2007. J.A. Hayman, K.M. Langa, M.U. Kobeto, et al., Estimating the cost of informal caregiving for elderly patients with cancer, J. Clin. Oncol. 19 (2001) 3219–3225. K.M. Langa, M.E. Chernew, M.U. Kabeto, et al., National estimates of the quantity and cost of informal caregiving for the elderly with dementia, J. Gen. Intern. Med. 16 (2001) 770–778. S. Chatterjee, A. Riewpaiboon, P. Piyauthakit, et al., Cost of diabetes and its complications in Thailand: a complete picture of economic burden, Health Soc. Care Commun. 19 (2011) doi:10.1111/j.1365-2524.2010.00981.x.
Contents lists available at ScienceDirect
Primary Care Diabetes journal homepage: http://www.elsevier.com/locate/pcd
Original research
Cost of informal care for diabetic patients in Thailand Susmita Chatterjee a , Arthorn Riewpaiboon a,∗ , Piyanuch Piyauthakit b , Wachara Riewpaiboon c a
Division of Social and Administrative Pharmacy, Department of Pharmacy, Faculty of Pharmacy, Mahidol University, 447, Sri Ayutthaya Road, Bangkok 10400, Thailand b Waritchaphum Hospital, 83 Moo 13 Waritchaphum sub-district, Waritchaphum District, Sakhon Nakhon 47150, Thailand c Health promotion program for people with disability, Health System Research Institute, Ministry of Public Health, Tivanond Road, Nonthaburi 11000, Thailand
a r t i c l e
i n f o
a b s t r a c t
Article history:
Aims: The study estimated the cost of informal care for 475 randomly selected diabetic
Received 3 August 2010
patients as identified by International Classification of Diseases, tenth revision (ICD-10
Received in revised form
codes = E10–E14) and who received treatment at Waritchaphum hospital in Sakhon Nakhon
11 November 2010
province of Thailand during the financial year 2008.
Accepted 22 January 2011
Methods: Informal care was valued by using revealed preference method. Information of
Available online 18 February 2011
informal caregiving was collected through direct personal interview method either from
Keywords:
by using recall method.
the patients or from the caregivers. The data on time spent for informal care were collected Cost
Results: The study covered a total of 190 informal caregivers. Average time spent on informal
Informal care
care was 112.38 h per month. The estimated cost of informal care was USD 110,713.08 using
Diabetes
opportunity cost approach and USD 93,896.52 using proxy good method in 2008 (1 USD = 32
Revealed preference method
Thai Baht).
Caregivers
Conclusions: The study concluded that the hidden cost associated with informal caregiving is
Thailand
a burden for the Thai society. Hence, the economic cost associated with informal caregiving should be considered for future analyses of both the public health consequences of diabetes and interventions aimed at decreasing diabetic complications. © 2011 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.
1.
Introduction
Diabetes is a common chronic disease with increasing burdens in Thailand [1]. The national prevalence of diabetes in Thai adults aged ≥35 years was estimated 9.6% in 2000 and 6.7% among people aged ≥15 years in 2004 [2,3]. The high prevalence of diabetes leads to an increase in preva-
∗
lence of diabetic complications. The chronic nature of the disease and its devastating complications make it a very costly disease. In Thailand there exist some studies which tried to estimate the cost of diabetes, however, these studies focused either on provider or patient perspective, hence, one cost component namely the cost of informal care had never been evaluated [4–6]. Even in other countries, where societal perspective was used to estimate cost of diabetes, this cost
Corresponding author. Tel.: +66 2644 8678 91x5745; fax: +66 2644 8694. E-mail addresses: s chatterjee [email protected] (S. Chatterjee), [email protected] (A. Riewpaiboon), [email protected] (P. Piyauthakit), [email protected] (W. Riewpaiboon). 1751-9918/$ – see front matter © 2011 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.pcd.2011.01.004
110
p r i m a r y c a r e d i a b e t e s 5 ( 2 0 1 1 ) 109–115
component was ignored [7,8]. The only study that evaluated cost of informal care for elderly individuals with diabetes in the US found that the cost was between USD 3 and 6 billion per year, similar to the estimates of the annual paid long term care cost attributable to diabetes [9]. This emphasized the importance of valuing the hidden cost related to informal care in cost of illness analysis following societal perspective. Cost calculations and economic evaluations excluding informal care might suggest interventions to be cost saving or cost effective, but this result might be simply because of the exclusion of cost of informal care from the analysis [10,11]. ‘Informal care’ is the name given to the care provided by people from a care recipient’s social network: family, friends, acquaintances or neighbors [12]. Schulz and Beach reported that providing informal care can be stressful and may increase informal caregivers’ morbidity and mortality risks [13]. Hence, in economic terms, the evidence for informal caregivers’ increased morbidity and mortality risks due to providing informal care implies that informal care is not free when viewed over the medium and long term. Even in the short term, the provision of informal care is not free, at the very least it entails opportunity cost in terms of foregone paid work, unpaid work and leisure [14–18]. Hence, determining the cost of informal care is important in formulating health policy, because it reveals society’s opportunity costs of caring for people with various diseases and what could be saved by eradicating them [19]. Though relatively little research had focused specifically on informal caregiving for diabetes [9,20], a significant literature exist regarding the economic effects of informal caregiving for dementia and stroke [21–26]. Most studies had found that the cost associated with unpaid informal caregiver time account for a majority of the total cost of the disease. Given this backdrop, the objective of the present study was to estimate the cost of informal care for the diabetic patients at a public district hospital in Thailand.
2.
Methods
2.1.
Study site and study population
The study was conducted at Waritchaphum hospital, a public district hospital in Waritchaphum district of Sakhon Nakhon province in Thailand. As the present study was the first study which estimated cost of informal care for diabetic patients in Thailand, hence, there was no sufficient background information to calculate a formal sample size for this study. Based on available resources [27] and sample size used in one informal care study in Thailand [26], for this study the sample size was fixed at 475. A total of 1415 diabetic patients (inpatients and outpatients taken together) received treatment from the study hospital in 2008. Assuming non-availability and refusal rate of 15%, 546 patients were randomly selected from the electronic diabetic patient database of the study hospital and were targeted to be sequentially contacted for this study. The study team stopped contacting patients as soon as complete data were available from 475 diabetic patients (the pre-determined sample size for this study). When contacted for interview,
five patients were not available and three refused to be interviewed. Information of informal caregiving was collected through direct personal interview method either from the patients or from the caregivers. The caregivers were approached when the patients were not sure about the activities of their informal caregivers. A structured pre-tested questionnaire was administered to obtain those information. The data collection was done by a team of trained health centre and hospital staff of Waritchaphum district during January and March 2009. The study got ethical clearance from the Institutional Review Board of Mahidol University, Bangkok, Thailand. Written informed consent was obtained from all respondents who participated in this study.
2.2.
Conceptual framework of informal care
There are several methods for measurement of time of informal care. The most important methods are the diary, considered the gold standard, and the recall method [11]. In diary method, respondents are asked to write down all their activities during a specific period of time. This method has an important disadvantage as it requires a lot of time and effort from the respondents and is also very costly for the researchers. Therefore this method cannot be used in all situations. A less demanding method like recall method is then preferred, even though a major concern with this retrospective way of questioning is its reliability because of recall bias [11]. Given this disadvantage, for convenience, in this study the data on time spent for informal care were collected by using recall method. The recall period was 1 month prior from the date of interview. In this study, it was hypothesized that the informal care was needed for activities of daily living (ADL), household activities of daily living (HDL) and instrumental activities of daily living (IADL). These concepts were followed from Van den Berg et al. [28]. For treating diabetes and its complications, a number of medications are required. Further, as the disease becomes severe, the medical regimen becomes complex. Hence, the diabetic patients need help for managing medications, glucose monitoring, foot care, etc. To capture these, an additional activity namely health care activities (HCA) was added. Informal caregivers were asked how many minutes per day they spent on all the activities taken together mentioned under HCA. The ADL include personal care, moving around in the house, going to the toilet, bathing, dressing, eating and drinking, etc. Here also they were asked how many minutes they spent per day on all the activities taken together mentioned under ADL. The HDL includes preparation of food and drinks, cleaning the house, dishes, washing, ironing, sewing, etc. For the activities under HDL, informal caregivers were asked how many hours per day they spent on all these activities taken together. IADL include making trips and visiting family or friends, health care contacts, going to the bank, etc. The time spent on all the activities taken together under IADL was measured in hours per month. While asking these questions, it was made clear that only the additional part of housework due to the disease of the care recipient should be counted as informal care.
p r i m a r y c a r e d i a b e t e s 5 ( 2 0 1 1 ) 109–115
111
Total respondent N=475
Informal Caregiver (Yes) n=142
Informal Caregiver (No) n=333
One Caregiver (n=104)
Two Caregivers (n=28)
Three Caregivers (n=10)
Number of caregivers 104x1=104
Number of caregivers 28x2=56
Number of caregivers 10x3=30
Total Number of Caregivers = 190
Fig. 1 – Distribution of informal caregivers (N = 190).
2.3.
Valuation methods for informal care
The major problem in valuing informal care is that by definition no market prices exist [10]. It is often argued that informal care should be valued with the opportunity cost method [18,29,30]. The opportunity costs of informal care are the informal caregivers’ benefits foregone due to spending time on providing informal care. In opportunity cost approach, time can be valued in two ways viz. productivity cost approach and time cost approach. The productivity cost approach covers time of caregivers who still work while time cost approach covers the time spent by all caregivers. An alternative, proxy good method, is also proposed [30]. This method values time spent on informal care at the labour market price of a close market substitute. The opportunity cost method and proxy good method are termed as revealed preference method. Informal care can be valued by stated preference method as well like contingent valuation method and conjoint valuation method [31,32]. However, opportunity costs and proxy good methods are most advocated and most often used. One important reason for recommendations to use either one of these methods may be their relatively straightforward application [28]. Hence, in this study, informal care was valued by using revealed preference method. While valuing informal care by opportunity cost approach, time-cost approach was followed and minimum official wage rate of Sakhon Nakhon province, USD 4.63 per day (1 USD = 32 Thai Baht) was used as the base case [33]. As majority of the informal caregivers were either agriculturists or labourers, they did not have regular income. Further, some of them might had earned more than the minimum official wage while some others earned less than that, hence, in order to average out the differences in earning power of the informal caregivers, minimum wage rate was used. For valuing informal care using proxy good method, earnings (defined as wage plus other monetary and non-monetary benefits such as bonus, overtime, meal, etc.) from household work and from health and social work in 2003 were used. Nominal wages for 2008 (the study year) were calculated using 2003 wages and the consumer price index. According to the Labour Protection Act B.E. 2541, working time per week cannot exceed 48 h. Based on this, a total working time per month of 192 h was used to calculate the hourly wage rate. Earnings from health and social work USD 3.03 per day for Sakhon Nakhon were used for both HCA and ADL while earning from household
work USD 4.47 per day for Sakhon Nakhon was used for both HDL and IADL [34]. A sensitivity analysis examines the effect on the study results of systematic changes in key assumptions or parameters. In order to capture how the assumption of use of minimum wage rate of Sakhon Nakhon province affected the cost of informal care in opportunity cost method, sensitivity analysis was conducted by using minimum wage rate for the country as a whole. In proxy good method, one-way sensitivity analysis was performed by using the earnings for the country as a whole from the respective work, i.e. USD 4.78 per day for household work and USD 5.16 per day for health and social work.
3.
Results
3.1. Characteristics of the informal caregivers and the care recipients Among 475 study participants, 142 (29.9%) reported that they had informal caregivers. One hundred and four (21.89%) study participants had one informal caregiver, 28 (5.89%) had two informal caregivers and 10 (2.10%) participants had three caregivers. Thus the present study covered a total of 190 informal caregivers. The distribution is presented in Fig. 1. The mean ± standard deviation (SD) age of the informal caregivers was 45.28 (±16.65) years with maximum and minimum age 79 years and 9 years, respectively (Table 1). Females were relatively more engaged in informal caregiving as compared to their male counterparts (52.6% vs. 47.4%), although differences were small. Most of the informal caregivers had primary education (65.3%) and were engaged in farming (52.6%). Sons/daughters of the patients commonly served as informal caregiver (40.5%), however, spouses were also significantly engaged in informal caregiving (35.3%). Most of the informal caregivers were married (76.3%) and shared the same houses with the care recipients (87.4%). While looking at the characteristics of the care recipients, it was found that they had higher mean age as compared to those who did not need informal caregivers (p = 0.001) (Table 2). Group comparisons were done by unpaired t test and statistical significance was declared when p value was less than 0.05. The presence of complications and disability (as measured by
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p r i m a r y c a r e d i a b e t e s 5 ( 2 0 1 1 ) 109–115
Table 1 – Characteristics of informal caregivers (N = 190). Characteristics Age Less than 25 years 25–34 years 35–44 years 45–54 years 55–64 years 65 years and above Gender Male Female Marital status Single Married Divorced/widow Education Primary education Secondary education Diploma Bachelor degree Occupation Housewife Agriculturist Labour Student Govt. officials Retired person Others Relation with the patient Parents Spouse Children In-laws Brother/sister Grand children Others Living arrangements Same house with the patient Others Transport for those staying outside Walk Motorcycle Others
Number
Percentage
22 30 41 32 41 24
11.58 15.79 21.58 16.84 21.58 12.63
90 100
47.40 52.60
34 145 11
17.90 76.30 5.80
124 49 2 15
65.30 25.80 1.10 7.90
8 100 38 13 13 14 4
4.20 52.60 20.00 6.80 6.80 7.40 2.10
4 67 77 16 7 15 4
2.10 35.30 40.50 8.40 3.70 7.90 2.10
166 24
87.40 12.60
12 8 4
50.00 33.33 16.67
3.2. care
Time foregone and monetary value of informal
The informal caregivers spent maximum time in performing HDL (Table 3). Their mean (±SD) time spent on HDL was 42.21 (±39.94) hours per month, followed by IADL (mean ± SD = 9.28 ± 25.90), ADL (mean ± SD = 6.79 ± 15.45) and HCA (mean ± SD = 5.80 ± 10.13). As regards mean monetary value of informal caregiving, as per opportunity cost approach the same was USD 37.17 per month while as per proxy good method it was USD 33.54 per month. To analyze robustness of results, sensitivity analysis was conducted. In case of opportunity cost approach, country minimum wage rate was used for sensitivity analysis and for proxy good method country average earnings from household work and from health and social work were considered. The recalculation results showed that for opportunity cost approach, the mean cost increased by 7% while for proxy good method, the same increased by 16%.
4.
using Barthel index score) was significantly higher among the care recipients as compared to their counterparts [35]. Further, the care recipients had higher hospitalization rate and they visited more frequently to the provincial hospital.
Discussion
The demographic characteristics of the study sample were similar to those of all diabetic patients received treatment from the study hospital during the study period. For example, mean age and percentage of female patients in all diabetic patients at the study hospital were 59.77 years and 73% respectively while the same for the study sample was 59.34 years and 74.5%, respectively. As regards disease characteristics of the study participants, the mean duration of the disease was 7.20 years, most of the patients had type 2 diabetes (99%) and the mean fasting blood sugar level was 156.06 mg/dl. All these results are also comparable with other diabetic studies in Thailand. For example, Nitiyanant et al., Riewpaiboon et al. and Chaikledkaew et al. found 94.7%, 94%, 96% and 99% type 2 diabetic patients respectively in their studies in Thailand [1,6,36,37]. Nitiyanant et al. noted average disease duration 6.2 and 8.7 years respectively and fasting blood sugar level 167.27 and 150.91 mg/dl respectively among the diabetic patients in Thailand [1,36]. The characteristics of the informal caregivers in the present study were quite similar to those found in a recent study on informal care of disabled stroke survivors in Thailand [26]. The mean age of the informal caregivers in the present study was 45 years while the same for the other study was 46 years. Both studies found that the females were relatively more engaged in informal caregiving. This was probably because of typical
Table 2 – Characteristics of the care recipients. Characteristics
Caregiver Yes
Duration of the disease (mean ± SD) Age (mean ± SD) Fasting blood sugar level (mean ± SD) Presence of co-morbidity (%) Presence of complications (%) Presence of disability (%) Rate of hospitalization (%) Visit to provincial hospital (%)
8.28 ± 6.34 62.22 ± 12.31 158.32 ± 42.21 68.31 47.89 29.58 24.65 14.08
P value No 6.74 ± 6.38 58.13 ± 10.78 155.13 ± 35.31 63.36 24.02 6.61 6.91 6.01
0.160 0.001 0.435 0.296 0.000 0.000 0.000 0.013
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Table 3 – Time foregone and monetary value of informal care (N = 190). Time spent on (hours per month)
Mean
HCA ADL HDL IADL
5.80 6.79 42.21 9.28
SD
Median
10.13 15.45 39.94 25.90
0.00 0.00 30.00 2.00
Cost per month (USD)
Mean
Median
Inter-quartile range
Opportunity cost method Proxy good method Sensitivity – opportunity cost method Sensitivity – proxy good method
37.17 33.54 39.80 38.89
26.77 22.63 28.67 28.15
9.28–52.20 6.53–50.29 9.94–55.90 10.24–53.78
HCA = health care activities, e.g. taking medicines; ADL = activities of daily living, e.g. eating and dressing; HDL = household activities of daily living, e.g. shopping and preparing food; IADL = instrumental activities of daily living, e.g. visit to the clinic and relatives.
Thai family culture where females are primarily responsible for household tasks, including providing care to all family members including sick or disabled persons. However, several other studies conducted in different parts of the world also noticed that the females actually provided more informal care than males. Further, sons/daughters of the patients commonly served as informal caregivers followed by the spouses. This finding was also similar with the study in Thailand as well as studies in other countries [15,21,26,38]. As diabetes is a chronic illness and generally has an onset in mid life and reveal complications and consequently disability in the late life, sons/daughters or spouses were found mostly serving as informal caregivers instead of parents who usually serve as informal caregivers in case of life-long disability. While looking at the informal caregivers’ time spent on different activities, it was found that maximum time was spent for HDL. This finding was consistent with Van den Berg et al. where time spent by the informal caregivers was calculated for stroke and rheumatoid arthritis patients in The Netherlands but contradicted the finding of a recent stroke study in Thailand where it was found that most caregivers performed ADL tasks followed by HDL tasks [28,39]. Even though diabetes, stroke and rheumatoid arthritis all are chronic illnesses but stroke is an acute condition with immediate acute mobility disability while both diabetes and rheumatoid arthritis are slowly progressive chronic disease with slow progression of disability. Because of the progressive onset of disability among the diabetic patients, probably they mostly needed help for HDL tasks followed by IADL. As per the Thai culture, the sick or elderly persons are generally taken care of by their family members and there are several cases where the patients cannot access the rehabilitation services for improving their functional capacity to perform even the ADL. This is probably another reason for the caregivers performed more ADL tasks in case of disabled stroke survivors in Thailand. Another possible reason of longer time spent on HDL activities by the informal caregivers of diabetic patients could be that “normal” HDL tasks were not fully separated from additional HDL task. This reason was mentioned by Van den Berg et al. as well [28]. There exist some studies which incorporated HDL tasks mentioned in this study under IADL [40,41]. If these two types are clubbed in the present study, the informal caregivers were found to spend on average 51.5 h per month on the new broad IADL category.
The cost of informal care was calculated by using both opportunity cost and proxy good method. Several studies had shown that the opportunity cost method yielded lower results than the proxy good method [21,25]. However, contrary to those studies, in the present study the cost of informal care was lower in case of proxy good method (USD 6372 per month) as compared to opportunity cost method (USD 7062 per month). This was because those studies calculated only the cost of informal caregivers’ leisure time foregone and therefore, opportunity cost was valued at one-third of the average wage or minimum wage rate. However, in the present study, no differentiation was made between foregone paid, unpaid and leisure work, hence, all these foregone activities were valued equally by using official average minimum wage of Sakhon Nakhon province. Further, the earnings from health and social work (USD 3.03 per day) and from household work (USD 4.47 per day) which were used to calculate cost as per proxy good method were lower than the minimum average wage used to calculate cost as per opportunity cost method (USD 4.63 per day). Hence, the cost obtained using proxy good method was lower than the same obtained from opportunity cost approach. Apart from the economic burden, there is growing evidence that informal care has adverse effects on informal caregivers in terms of quality of life [13]. Further, providing informal care affects labour market participation [14]. In the present study, most of the caregivers (about 54%) were in the most productive age group of 25–54 years. The average time spent on informal care was 112.38 h per month. This might have some impact on labour market participation in the Thai society. On the other hand, increased labour market participation would reduce the supply of informal care, which in turn, would force some care recipients to accept institutionalized care instead of being cared for at home which would be more costly from a health care budget perspective. Another point to note here is that among 142 study participants who reported to have informal caregivers, 35 (about 25%) were hospitalized during the study period. The average cost of informal care (using opportunity cost approach) for the hospitalized patients was USD 79.87 as compared to USD 60.10 (p = 0.17) for the non-hospitalized patients. Hence, while allocating funds for health care, the policy makers should use the information on cost of informal care as well as other factors related to informal care. An increased attention for informal care is also important as the
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demand for informal care is likely to increase in future due to the aging of the Thai population. The following potential limitations of the present study merit comment. First, the time spent for informal care was recorded by using recall method while the diary method is considered as gold standard. However, given the disadvantages attached with diary method such as it requires a lot of time and effort from the respondents and the cost involves in applying this method, a less demanding method, i.e. the recall method is preferred. Second, it was found that the informal caregivers spent maximum time on HDL and that time was significantly higher than times spent for all other activities. One possible reason of such finding could be that “normal” HDL tasks were not fully separated from additional HDL task. However, in this study no attempts were made to compare HDL performed by general population and the study caregivers. Even though during the survey it was mentioned repeatedly that only the additional part of housework due to the disease of the care recipient should be counted as informal care, but still it may be difficult for respondents, especially in cases where informal care has been provided many years already, to distinguish between normal tasks and informal care. Hence, the estimates presented in this study particularly related to HDL might be a bit overestimated. Third, due to lack of necessary data, this study was unable to assess whether informal care was associated with significant negative health effects among caregivers. Future research should focus on whether such negative health effects occur and if so, whether these are unique aspects of diabetes caregiving. Such research would help guide potential caregiver interventions aimed at reducing the negative health outcomes of the caregivers. The present study concluded that the hidden cost associated with informal caregiving is a burden for the Thai society. A recent study estimated cost of diabetes from societal perspective in Thailand and found that the cost of informal care was the highest individual cost component in total cost of illness of diabetes (about 28%) and for that the contribution of direct non-medical cost was the highest in total cost of diabetes (about 40%) while the contributions of direct medical cost and indirect cost were 23% and 37%, respectively [42]. Hence, the policy makers should consider the economic cost associated with informal caregiving for future analyses of both the public health consequences of diabetes and interventions aimed at decreasing diabetic complications. However, to strengthen this argument a large-scale study to estimate cost of informal care among the diabetic patients in Thailand should be conducted as the present study reported the estimates for 475 diabetic patients in a public district hospital in Thailand.
Conflict of interest statement No conflicts of interest have been declared.
Acknowledgements The present study was a part of the research project under the fellowship program “Asia Fellows Awards 2008–09 (Cohort 10)” of the first author. The fellowship program was administered
by the Asian Scholarship Foundation, Bangkok, Thailand and funded by the Ford Foundation. We express our gratitude to the Asian Scholarship Foundation, Bangkok, Thailand for providing the opportunity of conducting the research. We are grateful to the National Research Council of Thailand for giving permission of conducting the present study in Thailand. We thank Faculty of Pharmacy, Mahidol University, Bangkok, for being the host institute of the research project. Special thanks go to the professors and students of Division of Social and Administrative Pharmacy, Department of Pharmacy, Mahidol University for their help and support at various stages of this research. Finally, we are indebted to all staff of Waritchaphum hospital and health centres for their support and co-operation during data collection.
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