712 Statistical package for the social sciences (SPSS) (1999) 15.0 ed. SPSS, Chicago, IL Tuomi K, Ilmarinen J, Jahkola A, Katajarinne L, Tulkki A (1998) Work ability index. Finnish Institute of Occupational Health, Helsinki van den Heuvel SG, IJmker S, Blatter BM, de Korte EM (2007) Loss of productivity due to neck/shoulder symptoms and hand/arm Int Arch Occup Environ Health (2011) 84:705–712 symptoms: results from the PROMO-study. J Occup Rehabil 17:370–382 Werner EL, Cote P (2009) Low back pain and determinants of sickness absence. Eur J Gen Pract 15:74–79 123