Work 49 (2014) 245–255 245DOI 10.3233/WOR-131726IOS Press

Associations between prognosed future workcapacity among long-term sickness absenteesand their actual work incapacity two yearslater

Göran Lundh∗, Klas Gustafsson, Jürgen Linder, Pia Svedberg, Kristina Alexanderson andStaffan MarklundDepartment of Clinical Neuroscience, Division of Insurance Medicine, Karolinska Institutet, Stockholm, Sweden

Received 16 May 2012

Accepted 15 April 2013

Abstract.BACKGROUND: Studies indicate that long-term sickness absence reduces the ability to return to work (RTW). Multidisci-plinary medical assessments (MMA) have been used as a method to receive a more versatile assessment of long-term sicknessabsentees (LTSA) and thereby a better basis for adequate medical and vocational rehabilitation, and an increasing ability tomaintain or regain work capacity.OBJECTIVE: The objective of this study was to investigate the associations between the prognoses of LTSAs’ future workcapacity made at a MMA and the assessments of their work incapacity made by the Social Insurance Offices (SIO) two yearslater.PARTICIPANTS: 385 LTSAs referred to an MMA by SIOs in the Stockholm area in Sweden between 2001 and 2006.METHODS: Data was collected at the MMA on demographic factors, health, diagnoses, and future work capacity. Informationon SIO decisions on sickness benefits and disability pension and what measures the SIO had taken was extracted from the casefiles at the SIOs. Descriptive statistics and multiple regression analyses were used to assess the associations between the prognosisand decisions on benefits, controlling for individual factors.RESULTS: Of those predicted to be able to maintain or regain work capacity, 68% received full-time benefits two years later.Work capacity was negatively affected by high age, full time sickness absence at MMA and number of physical symptoms atMMA. The prognosis at the MMA was not significantly related to work capacity when socio-demographic and health factors werecontrolled for. However, this was partly due to the fact that the MMA also included recommendations for vocational rehabilitationand that this factor had an effect on assessed work incapacity after two years.CONCLUSION: The prognosis of future work capacity evaluated at a multidisciplinary medical assessment correlated withactual work capacity two years later. However, a range of other factors were decisive for the result. The study shows that thelink between the prognosis and recommendations for vocational rehabilitation should be followed by the SIOs responsible forenhancing RTW among individuals on long-term sick leave.

Keywords: Sick leave, work capacity, disability pension, multidisciplinary medical assessment

∗Corresponding author: Göran Lundh, Department of ClinicalNeuroscience, Division of Insurance Medicine, Karolinska Institutet,

SE-171 77 Stockholm, Sweden. Tel.: +46 8524 832 31; +46 7655555 06; Fax: +46 8524 832 05; E-mail: göran.lundh@ki.se.

1051-9815/14/$27.50 c© 2014 – IOS Press and the authors. All rights reserved

246 G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees

1. Introduction

People on long term sickness absence have in manycases a reduced future work capacity and an increasedthe risk of future disability pension (DP). Research re-views on factors affecting return to work (RTW) andDP after long term sickness absence has identified arange of demographic, health related, work related andother factors [1–6].

Among demographic factors, studies have foundthat female gender, high age, being foreign born, nothaving an employment relationship during sickness ab-sence and having low socio-economic status reducesthe probability to RTW or increases the risk for DP af-ter a spell of long term sickness absence [7–13].

Physical and psychosocial work conditions, organi-zational structures at work and stability of the employ-ment contract have also been found to affect RTW andDP among long term sick-listed [14–18]. Studies havealso found that sick-listed who report low self-ratedhealth has an increased risk of future DP [19,20].

Although there are differences depending on themedical diagnosis of individuals on long term sickleave, non-medical factors seem generally to play animportant role in RTW and DP after long term sicknessabsence [15,17,21,22]. Additionally, research on voca-tional rehabilitation has shown that demographic andwork related factors affect the degree to which suchrehabilitation measures are capable of increasing theprobability to RTW or reducing the risk for DP amongsick-listed [14,23–25].

Much less research has focused on the degree towhich it is possible to make a reasonable prognosisof future work capacity by using comprehensive med-ical or multidisciplinary assessments during the sick-ness absence period. Such assessments would ideallybe able to improve the selection to different formsof medical and vocational rehabilitation measures forlong-term sickness absentees. One exception of such astudy on assessment of future work capacity is Hunt etal conducted in 2002, which however studied patientsrather than long term sick-listed people [12]. The ob-jective of the study was to determine the prognosticvalue of a comprehensive medical assessment of fu-ture RTW among patients with low back pain. The re-sults showed only modest correlations between prog-nosis based on the medical assessments and RTW sta-tus three months later and that other than medical fac-tors may be of importance for prognosis of RTW.

In Sweden, the Social Insurance Office (SIO) canchoose to refer long-term sickness absentees (LTSA)

with ambiguous medical conditions and an unclearlevel of work incapacity to go through a multidisci-plinary medical assessment (MMA). The intent is toobtain a more thorough and accurate medical assess-ment, which could be used to promote adequate medi-cal and vocational rehabilitation and RTW. Three pre-vious studies [26–28] have analyzed the results of theMMAs performed at the Diagnostic Centre in Stock-holm during 2001–2006 and those found that most ofthe examined LTSAs had physical and/or mental dis-orders that reduced their work capacity, such as painand depression. The physicians performing the MMAprognosed that it would be possible for a majority ofthe LTSAs to maintain or regain their work capacitywithin two years provided they received proper medi-cal treatment and/or vocational rehabilitation.

Studying the outcome of the prognoses made at theMMA could contribute to further knowledge of factorswhich may or may not influence the possibilities forindividuals on long-term-sickness absence to maintainor regain work capacity.

The aim of the present study was to investigate theassociation between the prognosed future work capac-ity made at the MMAs and the SIO’s assessments ofwork incapacity of individuals in the same group twoyears later.

2. Methods

A prospective cohort study was conducted usingdata from surveys, medical files, SIO case files, andregisters.

2.1. Participants and procedure

The SIOs of Stockholm County in 2001–2006 re-ferred 635 individuals for an MMA at the DiagnosticCentre. Of these, 390 individuals referred by the fivelargest SIOs were chosen as study group. Three of the390 individuals were excluded as they were not receiv-ing sickness benefits or DP at the time of the referral,and another two were excluded as their future work ca-pacity was not assessed. Two of the five excluded indi-viduals had received DP at the time of the follow up.According to information from the Swedish Popula-tion Register, none of the individuals died or emigratedduring the two year follow up period. The remaining385 individuals were similar to the 635 regarding de-mographics and diagnoses (Table 1).

G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees 247

Table 1Comparison between 635 individuals referred to a MultidisciplinaryMedical Assessment (MMA) at the Diagnostic Centre 2001–2006and the study group. Percentage distribution

Original population Study groupn = 635 n = 385

SexWoman 63 60Man 37 40

Age at MMA (years)21–42 34 3443–51 40 3452–63 26 32

Country of birthSweden 62 61Other country 38 39

EducationElementary school or less 35 35High school 38 37University 27 28

Work status at MMAHaving a work contract 46 49No work contract 54 51

Diagnoses at MMASomatic only 25 26Somatic and psychiatric 55 55Psychiatric only 19 18No diagnosis 1 1

The MMAs involved three visits per patient withina time period of three weeks. The MMA examina-tion was conducted by three board-certified physi-cians: a specialist in psychiatry, orthopedic surgery,and rehabilitation medicine. A wide range of stan-dardized instruments were used to assess medical andnon-medical conditions [26,27,29]. The MMAs pro-duced information regarding diagnoses, prognoses ofwork capacity, and recommendations for medical treat-ment and vocational rehabilitation. Detailed informa-tion from the MMA was used in the analyses.

The results of the MMAs were sent to the SIO of-ficers who then evaluated the individuals’ rehabilita-tion needs and decided whether they were entitled tofurther sickness benefits. Of the 385 individuals 81were invited to coordination meetings with the officer,the treating physician, and a representative of the em-ployer or the employment agency to discuss and planfor RTW. In all, 88 individuals received vocational re-habilitation such as work adjustments, work training,or vocational education.

As mentioned above, a structured protocol was usedto extract information from the SIO case files on theinteractions between the SIO officers and the individ-uals, both pre- and post-MMA, and on the SIO’s de-cisions based on the results of the MMA, concerning

such matters as additional medical examinations andassessments after the MMA, coordination meetings,vocational rehabilitation measures, and litigation, e.g.,if the subject appealed to an administrative court aboutdecisions made by the SIO.

Data on sickness benefits and DP for the period1993–2009 were obtained from a database at theSwedish Social Insurance Agency called MiDAS (Mi-cro Data for Analysis of Social insurance). Duringthis period, a person could have sickness benefits formore than a year, a temporary DP that was re-evaluatedyearly, or a permanent DP. Furthermore, all of thesetypes of benefits could be for part- or full-time, and itwas possible to combine part-time sick-leave benefitswith part-time DP. Even if long-term sickness absent oron temporary DP, employees in Sweden have in mostcases the right to keep their employment contract, thatis, cannot be dismissed.

2.2. Measurements

2.2.1. PredictorThe MMA physicians made prognoses on whether

the LTSAs would be able to maintain or regain theirwork capacity within two years, provided that adequatemedical treatment and/or vocational rehabilitation wasgiven. The physicians’ assessments were used as pre-dictors and called prognosis of work capacity withintwo years (no or full-time/part-time). The MMA as-sessed that 79 of the 385 individuals were not expectedto be able to regain their work capacity at all withintwo years.

2.2.2. Outcome variableThe outcome variable used in the present study was

work incapacity two years after the MMA (no/part-time or full-time), operationalized as receiving sicknessbenefits and/or DP two years after the MMA. Not re-ceiving sickness benefits/DP or only receiving it parttime indicated that that the individual had been as-sessed to have some work capacity.

2.2.3. Other included factorsDemographic factors at the time of the MMA. These

included sex (man, woman), age group (21–42, 43–63 years), country of birth (Sweden, other country), ed-ucation (elementary, high school/university), and workstatus (having a work contract, no work contract). So-cial relationships (having many or hardly any socialcontacts at work and/or during leisure time) were di-

248 G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees

chotomized into no/few social contacts versus manysocial contacts.

Recommendation for vocational rehabilitation atMMA. The prognosis of work capacity within twoyears was in almost half of the cases made conditionalon recommendations for vocational rehabilitation. Thisfactor had only two values (yes or no).

SIO measures taken after the MMA. Two main indi-cators of measures taken by the SIOs were used. Thefirst was whether the SIO had arranged a coordinationmeeting within the two years following the MMA (yesor no), and the second was whether the SIO had offeredvocational rehabilitation (yes or no).

Sick leave before the MMA. Two variables were usedto measure length of sickness absence. The first wasthe number of net days receiving sickness benefitsand/or DP in the five years preceding the MMA (netdays were used to more accurately account for dayswith part-time benefits; for example, two days withhalf-time benefits were combined to one net day withsickness benefit), and the second was whether the per-son received full- or part-time sickness benefits/DP atthe time of the MMA referral.

Self-reported health at MMA. Five different mea-sures of health as reported at MMA were used in thestudy.

– General health. This was measured using the fiveitem index in the SF-36 instrument [30].

– Number of physical symptoms/functional impair-ments [29,31]. A check-list based on 16 dimen-sions in the International Classification of Func-tioning, Disability, and Health (ICF) was usedto measure symptoms and impairments [32]. Re-spondents marked yes or no to indicate whetherthey had any of 16 symptoms/functional im-pairments such as balance difficulties, sweating,numbness, muscular weakness, headaches, andfrequent tiredness [31]. The variable was di-chotomized using the median of 11, separatingthose below the median (0–10) from those on themedian and above (11–16).

– Pain locations. Based on the ICF procedure to re-gister pain location different pain areas were reg-istered [32]. The locations of pain were recordedusing a standardized pain drawing [33] with57 defined areas: 23 constituting the neck-shou-der-upper-extremity region, nine comprising thelumbosacral spine-thigh region, 12 for the knee-lower leg-foot region, and 13 for the head andthe rest of the body. The procedure used hasbeen described by others [29]. The variable was

dichotomized according to the median of themarked locations into median and below (0–20)or above the median (21–57).

– Difficulties in daily activities. A questionnairewas constructed on the basis of the ICF-classifi-cation to gather responses on 18 different phys-ical activities [32]. The activities correspondedto the categories in the Swedish version ICF-classification, consisting of mobility (e.g., grasp-ing objects, writing with a pencil, carrying bags ofgroceries), self-care (e.g., combing hair, using thetoilet), and household tasks (e.g., washing dishes,picking up objects from the floor, vacuuming) [29,31]. The items were added and the final variablewas dichotomized by using the median of the re-ported number of difficulties in the daily activitiesinto below median (0–8) or the median and above(9–18).

– Reduced sleep. Responses to a question on re-duced sleep in the Comprehensive Psychopatho-logical Rating Scale (CPRS-S-A) were used [34].The responses were dichotomized into the cate-gories of less than two hours versus two hours ormore of reduced sleep per day.

Medical diagnoses at MMA. The diagnoses deter-mined at the MMA were classified according to ICD-10 [35]. Many individuals received several diagnoses.The diagnoses were dichotomized into two groups: onefor those with somatic diagnoses only and one for thosewith either only psychiatric diagnoses or with a combi-nation of psychiatric and somatic diagnoses. Three in-dividuals did not receive any medical diagnoses at theMMA, one of whom was granted DP within the followup time.

2.3. Missing information

Information from the SIO case files was missing orincomplete for 17 individuals (4%) regarding pre- andpost-MMA contacts. No information was available for24 individuals (6%) regarding coordination meetingsand 14 individuals (4%) lacked information on offeredvocational rehabilitation during the follow up.

Figure 1 illustrates the associations studied betweenthe assessments of work capacity made at the MMAand those by the SIO, along with the confounders.

2.4. Statistical analyses

In the first step of the analysis, descriptive informa-tion and crude relative risks (RR) and confidence inter-

G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees 249

MMA assessment of future work capacity

� No work capacity � Work capacity in two years � Recommendation of

vocational rehabilitation

SIO activity after the MMA

� Coordination meeting � Vocational rehabilitation � No activity

SIO assessment of work incapacity two years after

the MMA � Decision to grant full-time

sickness benefits/DP

Factors affecting assessment of work capacity at MMA and SIO, and SIO measures

� Health factors � Previous sickness absence

� Demographic factors

Fig. 1. The associations studied between assessments of work capacity at the time of the Multidisciplinary Medical Assessment (MMA) andthose of the Social Insurance Office (SIO), and included confounders. DP = Disability Pension.

vals were calculated for the relationship of each factorand the assessed work incapacity at follow up. In a sec-ond step relative risks of each of the significant factorswere tested against the outcome in block wise multipleregressions in four different models. A modified pois-son regression approach for prospective studies withbinary data was applied [36]. In model 1 only progno-sis and demographic factors were included. In model2, health factors and diagnosis at MMA were addition-ally included. In model 3, vocational rehabilitation wasadditionally added. In the final model only factors thatsignificantly affected the outcome were included.

Due to the limited number of cases, all of the vari-ables were dichotomized to avoid zero-cell problems.All statistical analyses were conducted with SPSS, ver-sion 20 (SPSS, version 20.0, Inc., Chicago, Il.)

2.5. Ethics

The study was approved by the Regional Eth-ical Review Board in Stockholm, Sweden (1995-149, 2006/1281-31, 2008/71-31/5, 2008/1051-31/12and 2010/448-32).

3. Results

The prognoses of future work capacity from theMMAs estimated that 306 (79%) individuals would beable to maintain or regain full or partial work capac-

ity two years later and that 79 (21%) would remainincapable of working (Table 2). However, two yearslater 279 individuals (72%) were receiving full-timesickness benefits/DP, as the SIO had determined thatthey had no work capacity. Of the 79 individuals whoseprognosis at the MMA was that they would have nofuture work capacity, 71 (90%) later received full-timesickness benefits/DP. Furthermore, of the 306 individ-uals predicted to be able to maintain or regain theirwork capacity, 208 (68%) received full-time sicknessbenefits/DP two years later (Table 2).

Among the 306 individuals who were prognosed tobe able to maintain or regain work capacity, most of theincluded variables were associated with a higher riskof receiving full-time sickness benefits/DP at the timeof follow-up (Table 2). Higher age, not being born inSweden, having no work contract, few social contacts,many physical symptoms and difficulties with dailyactivities, reduced sleep, poor general health, havingmental diagnoses, not being recommended for voca-tional rehabilitation, having had a large number of dayswith sickness benefits/DP in the five years before theMMA, and receiving full-time sickness benefits/DP atthe time of the MMA referral (Table 2) were all as-sociated with this higher risk of receiving full-timesickness benefits or DP two years later. The resultsshowed that there were no significant differences be-tween women and men or between people with dif-ferent educational level. Vocational rehabilitation wasrecommended at the MMA for 41% of the individu-als but less than half of these were approved by the

250 G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees

Table 2Factors related to SIO’s assessed work incapacity two years after the MMA. Percentage distribution, crude relative risks (RR) with 95% confi-dence intervals calculated by Poissson regressions for binary data

Work incapacity assessed by SIO two years after MMAn % No/part time % Full time % Crude RR (CI)

MMA prognosis if work capacityNo or part time incapacity (ref) 306 79 32 68 1Full incapacity 79 21 10 90 1.32 (1.19–1.47)

SexMen (ref) 155 40 25 75 1Women 230 60 30 70 1.07 (0.95–1.21)

Age (years)21–42 (ref) 132 34 36 64 143–63 253 66 23 77 1.19 (1.03–1.38)

Country of birthSweden (ref) 236 61 32 68 1Other country 149 39 20 80 1.18 (1.05–1.33)

EducationHigh school or university (ref) 250 65 30 70 1Elementary school or less 135 35 24 76 0.92 (0.82–1.04)

Work statusHaving a work contract (ref) 188 49 38 62 1No work contract 197 51 18 82 1.32 (1.16–1.50)

Social relationshipsMany social contacts (ref) 126 33 43 57 1Few social contacts 258 67 20 80 1.40 (1.19–1.65)

Number of physical symptoms1

0–10 (ref) 183 48 36 64 1>10 201 52 20 80 1.24 (1.09–1.40)

Number of pain locations2

0–20 (ref) 197 52 33 6721–55 178 48 24 76 1.13 (1.00–1.29)

Number of difficulties in daily activities0–8 (ref) 190 49 36 649–18 195 51 20 80 1.25 (1.11–1.42)

Reduced sleep3

< 2 hours per night (ref) 164 43 35 652 hours or more per night 207 57 21 79 1.22 (1.07–1.39)

General health4

31–61, poor to average (ref) 212 56 20 80 10–30, very poor 171 44 37 63 1,28 (1.12–1.47)

Diagnostic category at MMA5

Somatic only (ref) 99 26 47 53 1Including psychiatric 284 74 21 79 1.47 (1.22–1.79)

Vocational rehabilitation recommended at MMANo (ref) 229 59 19 81 1Yes 156 41 40 60 1.36 (1.18–1.57)

Net days with sickness benefits/DP in five years before MMA0–911 days (ref) 192 50 34 66 1>911 days 193 50 21 79 1.21 (1.07–1.37)

Sickness benefits/DP at referral to MMAPart-time (ref) 58 15 72 28 1Full-time 327 85 20 80 2.92 (1,92–4.44)

Coordination meetings in two years after MMA6

No (ref) 280 78 24 76 1Yes 81 22 36 64 1.18 (0.99–1.41)

Vocational rehabilitation approved after MMA7

No (ref) 88 24 38 62 1Yes 275 76 23 77 0.82 (0.68–0.97)

Total 362–385 100 28 721One individual did not report physical symptoms. 2Ten individuals did not report number of pain locations. 3Fourteen individuals did notreport degree of reduced sleep. 4Two individuals did not report general health. 5Two individuals received no diagnosis. 6Data for 24 individualsmissing. 7Data for 22 individuals missing.

G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees 251

SIOs for such rehabilitation (not shown in table). Forthose who had an approval to get vocational rehabilita-tion during the follow up time, the outcome was signif-icantly more negative in terms of work capacity. Partic-ipation in coordination meetings did not correlate sig-nificantly with the outcome (Table 2).

The fifteen variables found to be significantly cor-related with work incapacity at follow-up were con-trolled for in a block-wise regression analysis (Ta-ble 3). Crude RR for the variable ‘degree of sick-ness benefits/DP’ was exceptionally high, but the CIwas wide. In model 1, prognosis of future work ca-pacity and four demographic variables were included.Apart from the prognosis, age, work status, and so-cial relationships remained significant, while countryof birth did not. In model 2, all health indicators wereincluded. In this model the predictor was no longer sig-nificantly related to work incapacity as assessed by theSIO. Degree of sickness benefits/DP and number ofphysical symptoms as well as age remained significant.In model 3, two indicators of vocational rehabilitationwere introduced. One of them, indicating if vocationalrehabilitation was recommended at the MMA, was sig-nificant together with the three factors that were signif-icant in model 2. Four variables remained significant inrelationship to work capacity at follow up in the finalmodel: age, degree of sickness benefits/DP, number ofphysical symptoms, and recommended vocational re-habilitation at MMA (Table 3).

4. Discussion

The aim of the study was to investigate whether theassessments of future work capacity made at an MMAcorresponded with the SIO’s determinations on sick-ness benefits and DP two years later. The results showthat a large share of the individuals who had been as-sessed to have a future work capicity were on full timesickness benefits or DP at follow up. There was, how-ever, also a correspondence between the prognosis andthe outcome in the sense that almost all that had beenassessed to have no future work ability were also onsickness benefits or DP.

The socio-demographic and health characteristics ofthe individuals were further studied in different steps.The prognosis remained significantly related to theoutcome even after control for socio-economic differ-ences. When differences in a range of health indica-tors were introduced, however, the effect of the prog-nosis disappeared. Work incapacity at follow-up was

found to correspond with higher age, number of phys-ical symptoms, receiving full-time sickness benefits atthe time of the MMA referral and not implemented rec-ommendations on vocational rehabilitation.

Associations between higher age and receiving sick-ness benefits/DP have been reported in several stud-ies [7,8]. In a systematic review of studies concerningthe causes for sickness absence [37], most of the stud-ies found that there were associations between higherage and receiving DP. However, according to the re-view, the causal mechanisms behind this associationhad been studied only to a minor extent. That higherage would be associated with an increased risk forDP is plausible since higher age carries with it an in-creased risk for age-related diseases. In the presentstudy higher age remained a significant factor even af-ter controlling for health factors. This is in line witha recent German study [38] where high work capac-ity was related to an appropriate relation between ef-fort and reward at work and good relaxation abilitiesat work rather than with calendar age itself. Chang etal. [39], concluded that the work capacity of ageingworkers is multifactorial, involving an interaction be-tween functional capacity, the nature of the work, andhealth. The importance of creating better age-adjustedand flexible working conditions to keep elderly in theworkforce has also been stressed by Ilmarinen [40] andRoss [41].

Having had full-time sickness benefits or DP at thetime of the MMA referral significantly increased therisk of receiving full-time benefits at follow-up. In arecent register study [42], individuals who had ini-tially been on part- or full-time sick leave for morethan six months were followed up. The study showedthat receiving partial benefits while also working parttime had favorable effects on future DP rates. Anotherstudy [43], reported that consultations with generalpractitioners using a structured functional assessmentof patients on sick leave for more than two months re-sulted in a greater portion of part-time sick leave com-pared with patients of general practitioners who did notuse a structured functional assessment. In a study usinga qualitative design [44], individuals on full-time DPreported that they had adapted to a life without workand had found other ways to increase their sense ofwell-being, whereas individuals on part-time DP ex-pressed a desire to work for as long as possible andsought ways to remain working. In a Dutch study [45]of patients with chronic arthritis, the main finding wasthat working for at least a few hours per week was veryimportant for their continued employment. The find-

252 G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees

Table 3Relative risks (RR) for work incapacity assessed by SIOs two years after a multidisciplinary medical assessment (MMA). Stepwise poissonregressions (RR), CI = 95%

Crude Model 1 Model 2 Model 3 Final modelRR (CI) RR (CI) RR (CI) RR (CI) RR (CI)

PredictorMMA prognosis if work capacity

No or part time incapacity 1.32 (1.19–1.47) 1.18 (1.06–1.31) 1.08 (0.96–1.21) 1.02 (0.91–1.13)Full incapacity 1 1 1 1

Demographic factorsAge

21–42 years (ref) 1 1 1 143–63 years 1.19 (1.03–1.37) 1.16 (1.01–1.33) 1.28 (1.11–1.48) 1.23 (1.07–1.42) 1.18 (1.04–1.33)

Country of birthSweden (ref) 1 1 1 1Other country 1.18 (1.05–1.33) 1.11 (0.99–1.24) 1.01 (0.90–1.15) 0.97 (0.86–1.09)

Work statusHaving a work contract (ref) 1 1 1 1No work contract 1.33 (1.17–1.51) 1.24 (1.10–1.40) 1.09 (0.96–1.23) 1.10 (0.97–1.25)

Social relationshipsMany social contacts 1 1 1 1Few social contacts 1.41 (1.20–1.66) 1.29 (1.10–1.51) 1.14 (0.96–1.35) 1.23 (0.95–1.32)

Sickness benefits/DP at referralNet days with sickness benefits/DP

0–911 (ref) 1 1 1>911 1.20 (1.06–1.36) 1.01 (0.97–1.14) 0.97 (0.86–1.09)

Degree of sickness benefits/DPNo/part time (ref) 1 1 1Full time 2.91 (1.91–4.43) 2.49 (1.65–3.77) 2.54 (1.67–3.87) 2.95 (1.96–4.44)

Health factors at MMANumber of physical symptoms

0–10 (ref) 1 1 111–16 1.41 (1.18–1.70) 1.19 (1.04–1.36) 1.15 (1.01–1.32) 1.18 (1.06–1.32)

Number of pain locations0–20 (ref) 1 1 121–55 1.15 (1.01–1.30) 0.95 (0.84–1.08) 0.92 (0.81–1.04)

Number of difficulties in activities0–8 (ref) 1 1 19–18 1.26 (1.11–1.42) 1.11 (0.97–1.28) 1.10 (0.96–1.26)

Reduced sleep<2 hours (ref) 1 1 12 hours or more 1.23 (1.07–1.40) 1.00 (0.87–1.15) 1.04 (0.91–1.19)

General healthGH >30 1 1 1GH 0–30 1.23 (1.12–1.47) 1.13 (0.99–1.28) 1.10 (0.97–1.25)

Diagnostic categorySomatic only (ref) 1 1 1Including psychiatric 1.48 (1.22–1.79) 1.15 (0.94–1.40) 1.10 (0.90–1.33)

RehabilitationVocational rehab recommended

Yes (ref) 1 1No 1.36 (1.18–1.57) 1.21 (1.04–1.40) 1.28 (1.12–1.46)

Vocational rehabilitation approvedYes (ref) 1 1No 0.81 (0.68–0.97) 0.92 (0.75–1.13)

Model 1: Control for demographic factors. Model 2: Additionally controlled for health factors. Model 3: Additionally controlled for vocationalrehabilitation. Final model: Control for only significant factors of model 3.

G. Lundh et al. / Associations between prognosed future work capacity among long-term sickness absentees 253

ings of these studies are consistent with the findings inour study.

We found no associations between the SIO’s deci-sions on vocational rehabilitation and receiving DP.Less than half of the individuals who at the MMAwere recommended to receive vocational rehabilita-tion were granted it by the SIO. This is in line withanother study [46], indicating that vocational reha-bilitation measures introduced by the SIOs were fartoo few and initiated unnecessarily late. Ahlgren etal. [47], came to a similar conclusion and also foundthat the process of selecting who is to receive rehabili-tation measures differed between the SIOs. In a review,Burstrom et al. [48] reported that selection for voca-tional rehabilitation was biased, and that the results ofthe rehabilitation were better for employed individualsand for those who had been on sick leave for a shortertime. Overall, the studies in this review found that vo-cational rehabilitation was not very effective for LT-SAs in terms of avoiding future DP. Andrén [49] foundthat participation in vocational rehabilitation actuallyincreased the risk for going on DP among LTSAs.

The fact that recommended vocational rehabilitationat MMA in many cases did not materialize may be oneof the reasons why there was no relationship betweenprognosed and actual work capacity in this study. It isnoticeable that having been recommended vocationalrehabilitation remained significant even after exces-sive control for the influence of potential confounders.Thus, a combination of a thorough multidisciplinaryassessment of a prognosis for future work ability andthe realization of the simultaneously suggested meansfor vocational rehabilitation may be a way to enhanceRTW among individuals on long term sick leave.

4.1. Strengths and limitations

The main strengths of the study were the extensiveand well-documented baseline information. The MMAand the study group could be followed up on one occa-sion two years later using high-quality national regis-ters without any drop outs. Moreover, the informationcollected from the SIOs enabled us to investigate howthose authorities used the MMA assessments. Such in-formation is rarely available for scientific investiga-tions.

A limitation was the lack of detailed informationabout the LTSAs’ work history and working condi-tions. Information about medical treatments and pos-sible health changes after the MMA was also lacking.Poor or unsuitable working conditions and deteriorated

medical conditions could have influenced the SIO’s de-cisions on full-time sickness benefits/DP.

The study group was relatively small and highly spe-cific in terms of the extended period of time they hadbeen on sick leave and their extensive health prob-lems. One main reason for the referral to an MMA wasthat the SIO staff was uncertain about the individu-als’ health conditions and potential for vocational reha-bilitation. Therefore, our results cannot be generalizedabout the potential effects of SIO’s activities on othergroups of LTSAs.

5. Conclusions

The study showed a poor relationship between theMMA assessed prognosis of future work capacity. Fac-tors such as high age, being on full time sick leave andreporting many physical symptoms influenced the de-gree to which the sick listed individuals remained sicklisted or had been granted DP two years later. The factthat the MMA recommended vocational rehabilitationshowed a relationship with future work capacity indi-cates that a medical assessment of future work abilitymust be accompanied by conducted measures of voca-tional rehabilitation in line with the recommendations.

Declaration of interest

No conflicts of interest were declared in relation tothis paper.

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