CENTER FOR REHABILITATION / REHABILITATION MEDICINE Deconditioning in Subjects with Chronic Musculoskeletal Pain; does Work Matter? Remko Soer 1,2 , Haitze J. de Vries 1 , Sandra Brouwer 3 , Johan W. Groothoff 3 , Jan H.B. Geertzen 1 , Michiel F. Reneman 1,2 1. Department of Rehabilitation Medicine, Center for Rehabilitation; 2. Groningen Spine Center; 3. Department of Health Sciences, Community and Occupational Medicine, University Medical Center Groningen, University of Groningen, the Netherlands. Contact information: Remko Soer, PhD., Center for Rehabilitation, University Medical Center Groningen, Phone *31-50-533 87 41, Email: r.soer@cvr.umcg.nl Objectives To study if absent workers with nonspecific chronic musculo- skeletal pain (CMP) are more often deconditioned for work compared to non-absent workers with and without CMP and to identify factors associated with deconditioning for work. A cross-sectional design with 3-group comparison was conducted. Deinition Deconditioned is defined as having insufficient FC to perform the required work demands. Methods A total of 942 workers were included in this cross sectional study, consisting of 122 absent workers with CMP referred to a rehabilitation center (CMP Absent), 119 non-absent workers with CMP (CMP working) and 701 healthy workers (HW). Characteristics are presented in Table 1. All subjects performed a Functional Capacity Evaluation (FCE). • T-tests, Mann-Whitney U tests and ANOVAs were applied to test differences between groups. • Logistic regressions were performed to analyze factors associated with deconditioned for work. Results Subjects with CMP Absent from work had significant lower FC compared to working subjects either with or without CMP (Table 2). Subjects with CMP were more often deconditioned (OR = 6.5 in CMP absent; OR=7.2 in CMP working) (Table 3). Factors associated with being deconditioned were: working in physically high demanding work (OR= 35.1), gender (OR=35.7) age (OR=1.2) and effort level during FCE (OR=1.9). In subjects with CMP, either working or absent, kinesiophobia (OR=1.1), physical health (OR=1.1) and perceived disability (OR=1.1) were significantly associated with being deconditioned for work. Conclusions Workers with CMP on sick leave were more often deconditioned compared to workers without sick leave. Having CMP is associated with being deconditioned in terms of insufficient FC for work. Working in physically demanding jobs, effort level during FCE and work status are important determinants for being deconditioned. Published as: Do Workers With Chronic Nonspecific Musculoskeletal Pain, With and Without Sick Leave, Have Lower Functional Capacity Compared With Healthy Workers? Archives of Physical Medicine and Rehabilitation. Epub ahead of print: July, 2012 Table 1: Baseline data of subjects Unit or scale CMP Absent CMP Working HW Gender male % 47.5 40.3 63.8 Age mean (sd) 39.6 (10.1) 48.3 (7.8) 41.4 (10.3) Sedentary work load % 19.5 34.4 17 Light work load % 33.1 35.3 32.7 Medium work load % 29.7 24.4 43.4 (very) heavy work load % 17.8 5.9 6.9 Pain intensity (NRS) 0-10; mean (sd) 6.1 (1.9) 4.6 (2.1) n.a. Pain self-eficacy (PSEQ) 0-60; mean (sd) 35.4 (11.8) 46.9 (8.5) n.a. Rand-36 PCS 0-100; mean (sd) 37.8 (12.5) 59.8 (17.9) 89.1 (9.3) Rand-36 MCS 0-100; mean (sd) 54.1 (20.0) 74.1 (17.0) 80.5 (12.1) Physical activity (Baecke) 3-15; mean (sd) 8.5 (1.1) 8.4 (1.2) 8.7 (1.3) Observed effort lifting low males (NRS) 0-10 6.1 (2.0) 8.2 (1.7) 8.2 (1.6) Observed effort lifting low females (NRS) 0-10 5.4 (2.3) 8.3 (1.8) 8.0 (1.9) CMP: chronic musculoskeletal pain; NRS: numeric rating scale; Rand-36 PCS: physical compo- nent summary; MCS: mental component summary; METS; metabolic equivalent Table 2: Differences in functional capacity between Absent workers with CMP, Workers with CMP and Healthy Workers Post Hoc Tuckey’s test Mean (sd) Absent workers with CMP Working with CMP Healthy Workers Lifting Low (kg) • Males • Females 27.0 (14.1) a,b 15.0 (7.2) a,b 34.7 (12.4) c 20.7 (6.4) c 48.0 (12.6) 26.7 (8.2) Lifting High (kg) • Males • Females 14.5 (5.3) b 9.2 (3.7) b 17.2 (4.2) c 9.9 (2.3) c 21.1 (5.2) 11.8 (3.4) Energetic capacity (METS) 9.4 (2.0) 9.1 (1.6) c 10.3 (1.9) Post Hoc Mann Whitney test Median (IQR) Overhead work (sec) * 108 (72-174) a,b 157 (113-226) c 240 (181-312) Static Bend (sec) * 148 (97-212) a,b 221 (150-287) c 287 (194-419) Dynamic Bend (sec) * 48 (44-54) b 51 (46-58) c 45 (41-49) * Kruskal-Wallis test; a Absent workers significantly different from Staying at Work ; b Absent Workers significantly different from HW; c Staying at Work significantly different from HW. Table 3: Logistic regression analysis of sufficient functional capacity to meet workload Model 1 Model 2 B Odds Ratio 95% CI of Odds Ratio B Odds Ratio 95% CI of Odds Ratio Constant 1.4 4.2 n/a -8.7 0 n/a SL-Rehab 1.9 6.5** 2.7 – 15.4 -0.2 1.2 0.2 – 9.2 SAW 2.0 7.2** 3.4 – 15.5 n/a n/a n/a Gender -3.6 35.7** 11.9– 100.0 -5.0 143** 13.2 – 1000 Age 0.03 1.0 0.9 – 1.0 0.18 1.2** 1.1 – 1.3 Observed effort -0.7 1.9** 1.6 – 2.3 -1.1 3.0** 1.8 – 5.1 Physical activity (Baecke) -0.1 1.1 0.9 – 1.5 0.1 1.1 0.6 – 1.9 Light work load 1.0 2.7* 1.1 -6.4 1.4 4.0 0.8 – 19.6 Medium work load 1.1 3.0* 1.1 – 7.7 0.1 1.1 0.2 – 6.4 Heavy work load 3.6 35.1** 7.6 – 162.5 3.9 50.6** 3.1 – 828.6 Kinesiophobia (TSK) n/a n/a n/a 0.1 1.1* 1.0 – 1.2 Rand-36 mental n/a n/a n/a -0.04 1.0 1.0-1.1 Rand-36 physical n/a n/a n/a 0.06 1.1* 1.0 – 1.1 Pain n/a n/a n/a -0.1 1.1 0.8 – 1.5 Disability (PDI) n/a n/a n/a 0.1 1.1* 1.0 – 1.2 Self Efficacy (PSEQ) n/a n/a n/a 0.0 1.1 1.1 – 1.2 Model 1: a three group comparison of Absent with CMP and Working with CMP compared to Healthy Workers (n=799); Model 2: a two group comparison of Absent with CMP com- pared to Working with CMP (n=138); PDI=Pain Disability Index; PSEQ=Pain Self Efficacy Questionnaire; *=<0.05; **<0.01