Santos et al. BMC Public Health 2011, 11:60 http://www.biomedcentral.com/1471-2458/11/60 Page 5 of 7 Table 1 Demographic and work-related characteristics of the study subjects* Intervention Group (n = 43) 30.6 (10.2) 26 (60.5) 36 (83.7) 20 (46.5) Control Group (n = 46) Age - mean (SD) 31.2 (8.8) Male 34 (73.9) Caucasians 42 (91.3) Married 26 (56.5) Educational status †: complete ES 2 (5.4) 6 (14.3) complete HS 32 (86.5) 32 (76.2) complete university 3 (8.1) 4 (9.5) Sector: administrative 20 (46.5) 18 (39.1) productive 23 (53.5) 28 (60.9) Medical condition 7 (16.3) 12 (26.1) Current use of medications 7 (16.3) 7 (15.2) Body Mass Index - mean (SD) 25.0 (3.0) 26.0 (2.9) Physical activity 26 (63.4) 28 (60.9) Years of work - median (percentiles 25, 75) 7.0 (3.0, 14.0) 10.5 (3.88, 19.0) Number of presences in the educational meetings - median (percentiles 25, 75) 6.0 (5.0, 6.0) 6.0 (5.0, 6.0) Baseline Physical functioning score - median (percentiles 25, 75) 95.0 (85.0, 100.0) 90.0 (85.0, 95.0) Baseline Work limitation questionnaire index (percent) - median (percentiles 25, 75) 2.76 (1.67, 3.63) 2.88 (1.10, 5.03) † Number of patients was 37 for the intervention group and 42 for the control group owing to missing data. Abbreviations: ES = elementary school; HS= high school. * Values are numbers (percentages), except where indicated otherwise. ** Student’s t test, Yates corrected chi-square, Fisher’s exact test or Mann-Whitney test was utilized according to the nature and distribution of data. Table 2 Comparison of the variation of the SF-36 and WLQ scores (between baseline and week 26) in the experimental groups Intervention Group Control Group Mean difference n Mean (SD) n Mean (SD) SF-36 scores Physical functioning 37 -1.49 (21.5) 38 0.92 (19.4) -2.41 Role physical 38 6.58 (24.4) 38 5.49 (34.6) 1.09 Bodily pain 39 10.9 (21.1)† 38 9.63 (22.4)† 1.27 General health 36 4.94 (10.4)† 36 2.64 (13.9) 2;31 Vitality 36 7.78 (16.2)† 37 6.76 (20.2) 1.02 Social functioning 35 6.43 (21.9) 36 11.11 (23.9)† -4.68 Role emotional 38 7.89 (39.8) 38 14.04 (35.2) -6.14 Mental health 39 8.37 (16.0)† 37 4.32 (16.5) 4.05 Physical component summary 34 5.04 (10.1)† 36 4.64 (16.2) 0.41 Mental component summary 31 8.55 (17.2)† 34 9.52 (19.4)† -0.97 WLQ scores Time management 36 0.56 (13.5) 35 -0.11 (14.3) 0.66 Physical demands 37 4.62 (32.5) 38 3.35 (38.3) 1.27 Mental-interpersonal demands 37 -2.10 (6.3) 37 -1.70 (11.6) -0.41 Output demands 38 -0.92 (9.4) 37 -5.95 (12.8)† 5.02 WLQ index (percent) 34 -0.18 (2.4) 34 -0.72 (3.2) 0.54 * Student’s t test. † P ≤ 0.01 by paired Student’s t comparing baseline and week 26 scores within the group. Abbreviations: SF-36 = Medical Outcomes Study 36 - Item short-form health survey; WLQ = Work Limitation Questionnaire. 95% CI P Value* -11.8, 7.0 -12.6, 14.8 -8.6, 11.2 -3.5, 8.1 -7.5, 9.6 -15.5, 6.2 -23.3, 11.0 -3.4, 11.5 -6.1, 6.9 -10.1, 8.1 -5.9, 7.2 -15.1, 17.6 -4.8, 3.9 -0.2,10.2 -0.8,1.8 0.613 0.874 0.800 0.428 0.813 0.393 0.479 0.281 0.900 0.832 0.841 0.877 0.853 0.057 0.435