Work and headache: a prospective study of psychological, social, and mechanical predictors of headache severity.

Headache is a common health complaint responsible for substantial suffering and disability. Although musculoskeletal complaints such as back and neck pain have frequently been associated with occupational psychological and social factors, headache has received less attention as a possible outcome of such exposures. The aim of the present study was to identify occupational psychological, social, and mechanical factors that predicted headache severity. Furthermore, using a full panel design, cross-lagged and synchronous structural equation models were employed to test reverse causality. Data were obtained by work environment surveys in a wide variety of organizations in Norway, with a two-year follow-up period. At baseline 6421 employees responded and 3574 employees also responded at follow-up. Ordinal logistic regression models revealed that 7 of 16 psychological/social/mechanical factors were prospectively related to headache severity. Most consistently, higher quantitative demands and role conflict, and lower decision control, control over work intensity, and job satisfaction were related to more severe headache at follow-up. Cross-lagged models indicated an impact across a 2-year period of decision control, control over work intensity, and job satisfaction on headache severity. Reverse effects from headache severity to quantitative demands were indicated. For role conflict, no cross-lagged effects were observed. However, synchronous models supported the notion of an effect of each of these factors on headache severity over a time span shorter than 2 years.