A short communication about the article “Assessment of the length of sick leave in patients with ischemic heart disease”

Page 7 of 10 A short communication about the article “Assessment of the length of sick leave in patients with ischemic heart disease” Nausica Català Tella1, Catalina Serna Arnaiz1, Jordi Real Gatius2,3, Oriol Yuguero Torres4 and Leonardo Galván Santiago5 1ABS Eixample, Institut Català de la Salut, Lleida, Spain 2Institut Universitari d’Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Lleida, Spain 3Facultat de Medicina i Ciències de la Salut, Universitat Internacional de Catalunya, Sant Cugat, Barcelona), Spain 4Servicio de Urgencias del Hospital Universitari Arnau de Vilanova, Lleida, Spain 5Servicio de farmacia, Departament Català de la Salut, Lleida, Spain


Background
Ischemic heart disease (IHD) is particularly important in our environment due to its high prevalence, the high consumption of resources it requires, and the associated mortality. The increase in its prevalence and advances in technology have established IHD as the disease with the greatest economic impact in the developed countries 1,2 . In recent decades, mortality rates after IHD have declined in developed countries, but IHD nonetheless remains the leading cause of death in men and the second most frequent in women 1,3 . Incapacity for work is one of the indirect costs of the disease, but this issue has not been widely studied 1,2,4,5 . Few authors have assessed the length of periods of sick leave due to IHD 1,6-10 since the review of the topic conducted in 2004 by Perk and Alexanderson 1,11 . The study by Sicras-Mainar in 2009 quantified the cost per patient following an episode of Acute Coronary Syndrome (ACS) at 14,069 euros (87% of which were direct costs and 13% lost productivity costs). The direct costs comprised primary care (20%) and specialized care (67%), with hospitalization costs accounting for 63% of the total 1,4 . Our aim is to determine the length of sick leave after an acute coronary syndrome, its costs, associated factors and to assess the use of antidepressants and/or anxiolytics 1 .

Methods
An observational study of a retrospective cohort of patients on sick leave due to ischemic heart disease in a health region of Catalonia, Spain, between 2008-2011, with follow-up until the first return to work, death, or end of the study (31/12/2012). Measurements: length of sick leave, sociodemographic variables and medical prescriptions. Data were obtained from the electronic medical record database of the primary care section (ECAP) of the Catalan Health Service and from the pharmacy billing databases run by CatSalut 1 .
The duration of sick leave was estimated by Kaplan-Meier survival analysis until the first medical discharge. The periods of sick leave were compared using the Log-Rank test, and at the multivariate level, hazards ratios were estimated by adjusting the Cox regression models. The assumption of proportional risks of the Cox models was evaluated using the Schofield residuals 1 .
Indirect costs were those relating to productivity loss (number of periods of sick leave and total days off work). They were quantified according to the minimum wage (Source: Spanish Institute of Statistics), considering the cost per day not worked at 54.65 euros 1,4 . Indirect costs were estimated for the whole of the patients' follow-up period 1 .

Results
Four hundred and ninety-seven patients (mean age 53 years, 90.7% male), diagnosed with acute myocardial infarction (60%), angina pectoris (20.7%) or chronic form of ischemic heart disease (19.1%). Thirty-seven per cent of patients took anxiolytics the year after diagnosis and 15% took antidepressants ( Table 1). The average duration of sick leave was 177 days (95% CI: 163-191 days). Patients diagnosed with acute myocardial infarction returned to work after a mean of 192 days, compared to 128 days in cases with angina pectoris (Fig.1). Patients who took antidepressants during the year after diagnosis returned to work after a mean of 240 days ( Table 2). Table 3 shows the multivariate analysis of the hazards ratios for returning to work depending on the variables analysed. The mean work productivity loss was estimated to be 9,673 euros/person 1 .

Probability of return to work
Length of sick leave period (Days)