The relationship between headache and chronic musculoskeletal complaints: an 11-year follow-up in the The Nord-Trøndelag Health Study (HUNT)

Background and aim Chronic daily headache (CDH) and chronic musculoskeletal complaints (CMSCs) are associated disorders, but whether there is a causal relationship between them is unclear.The aim of the study was to determine whether CMSCs are associated with the subsequent development of CDH and vice versa. Methods This longitudinal population-based cohort study used data from two consecutive surveys in the Nord-Trondelag Health Study (HUNT 2 and 3) performed in 1995-1997 and 2006-2008. Amongst the 51 383 participants aged ≥20 years at baseline, 41 766 were eligible approximately 11 years later. Of these, 26 197 (63%) completed the questions regarding headache and CMSCs in HUNT 3. Results A bidirectional relationship was found between headache and CMSCs. In the multivariate analyses adjusting for potential confounders, a nearly twofold risk (OR 1.8; 95% CI 1.5-2.3) for developing CDH was found for those with CMSCs at baseline. Vice versa, a similarly elevated risk of CMSCs (OR 1.8; 95% CI 1.2-2.6), and even higher risk of chronic widespread MSCs (OR 2.7; 95% CI 1.6-4.7), was found at follow-up amongst those with CDH at baseline.