BMC Public Health Research article Sickness absence poses a threat to the Swedish Welfare State: a cross-sectional study of sickness absence and self-reported illness Jan Sundquist*1, Ahmad Al-Windi1,2, Sven-Erik Johansson1 and Kristina Sundquist1 BioMed Central Open Access Address: 1Karolinska Institutet, Center for Family and Community Medicine, Alfred Nobels allé 12, SE-141 83 Huddinge, Sweden and 2University of Sulaimani, College of Medicine, Kurdistan, Iraq Email: Jan Sundquist* - jan.sundquist@ki.se; Ahmad Al-Windi - Ahmad.Al-Windi@ki.se; Sven-Erik Johansson - sven-erik.johansson@ki.se; Kristina Sundquist - kristina.sundquist@ki.se * Corresponding author Published: 2 April 2007 BMC Public Health 2007, 7:45 doi:10.1186/1471-2458-7-45 This article is available from: http://www.biomedcentral.com/1471-2458/7/45 Received: 14 August 2006 Accepted: 2 April 2007 © 2007 Sundquist et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: The increasing cost of public social sickness insurance poses a serious economic threat to the Swedish welfare state. In recent years, expenditures for social insurance in general, as well as social sickness insurance in particular, have risen steeply in Sweden. This cross-sectional study analyzed the association between sickness absence (SA) and self-reported reduced working capacity due to a longstanding illness (>3 months), as well between SA and a number of other health problems. Methods: Self-reported data on longstanding illness and resultant reduced working capacity, socioeconomic factors, working environment, psychosomatic complaints, anxiety, and general health were obtained for 22,281 employed (paid) persons aged 25 to 64 years. These data were retrieved from the Swedish Living Conditions Survey for 1995 to 2002. National civic registration numbers, replaced with serial numbers to ensure anonymity, were used to link these data to individual-level SA records from the National Social Insurance Board. A logistic regression model was used to estimate the odds ratio of the main outcome variable for the three levels of the SA variable (0–28, 29–90, >90 days/year). Results: There was an obvious increasing gradient in length of SA and increasing odds of reporting reduced working capacity. Odds ratios ranged from 3.5 to 19.0; i.e., those with more than ninety days of SA had 19.0 times higher odds of reporting reduced working capacity than those with 0– 28 days of SA a year. This very strong association changed less than 10% after adjusting for demographic, socioeconomic, and working environment characteristics. A total of 48.7% of persons on sick leave ≥ 29 days reported no longstanding illness and reduced working capacity. Of these persons, about 43% reported one or more other health problem. Conclusion: We confirmed that longstanding illness that results in self-reported reduced working capacity is an important variable related to length of SA, even after taking important confounders into consideration. We found a little less than half of those on sick leave reported no reduced working capacity due to longstanding illness, and some of these reported no other health problems. However, it is possible that some respondents had health problems not captured in the survey. Page 1 of 11 (page number not for citation purposes)