Impaired work ability and reduced well-being due to long-term musculoskeletal pain (MSP) in the neck, shoulder and back are considered occupational health problems that can result in workers taking sick leave (SL) [1–4]. Long-term SL, in particular, constitutes a major economic burden for society [5, 6]. Studies have shown that the prevalence and incidence of SL due to long-term MSP (≥ 3 months) is high among women [2, 7]. According to a recent report from the Swedish Social Insurance Agency (SIA), 61% of Swedes who are on SL for MSP are women . Studies have shown that individuals living with long-term MSP and on SL may experience negative consequences in life, such as depression, social isolation and reduced income, all of which could be associated with their impaired work ability and reduced well-being [9–11]. Work ability has been defined as a worker’s ability to manage his/her work task at a given point in time, in relation to his/her physical and psychosocial capacity [12, 13]. Well-being is a combination of physical, mental and social aspects that correspond to the level of life satisfaction in daily living [14, 15].
The importance of work ability and well-being for return to work (RTW) has previously been studied among people with MSP [3, 4, 16, 17]. Studies have suggested that an individual’s resources, such as personal beliefs in one’s ability to work, are associated with RTW among people with MSP [18, 19]. In contrast, workplace factors such as high demand and low control at work (job strain) have been shown to hinder workers in their RTW . Ratings of work ability are made in relation to the work performed. Because women and men have different work tasks even in the same job, the rated work ability – and its relation to RTW – may differ between female populations and populations consisting of both men and women .
Work ability and well-being may fluctuate over time depending on the work women do in their daily life. It has previously been reported that women have many responsibilities at home, such as shopping and cleaning, which tends to cause them to combine part-time work with unpaid work, i.e. family responsibilities [22, 23]. This extended work may restrict their recovery from MSP, which may influence their work ability and well-being, eventually influencing their RTW. Therefore, it may be interesting to study work ability and well-being to determine whether they facilitate RTW among women on SL for MSP.
The instruments used in this study are the Work Ability Index (WAI) and Life Satisfaction Questionnaire (LiSat-11). WAI is a commonly used instrument for assessing work ability  in relation to working life and rehabilitation. The LiSat-11 was originally developed for rehabilitation purposes ; in the present study, it was used to assess well-being among women on SL for long-term MSP. In previous studies, both instruments have been shown to be well validated and reliable [25, 26]. Thus, it is important to examine how well these instruments are able to discriminate between RTW and not RTW (NRTW). In addition, it is essential to ascertain whether the WAI and LiSat-11 instruments may be useful in screening women at risk of NRTW, as being on SL is an economic burden. To the authors’ knowledge, no previous study has investigated the discriminative ability of the WAI and LiSat-11 to detect RTW in women with long-term MSP.
Therefore, the aim was to determine whether work ability and well-being could predict RTW among women with long-term neck/shoulder and/or back pain at a 1-year follow-up, and to assess the ability of the WAI and LiSat-11 to discriminate between those who did RTW and those who did NRTW.