Neck pain : factors of importance for the risk and prognosis

Abstract

Introduction: Considering the recurring nature of neck pain, and that it is a big societal as well as individual burden, it is of great importance to increase the knowledge about what factors that affect the risk and prognosis of neck pain.

Objectives: The objective of this thesis was to study factors of potential importance for the risk and prognosis of neck pain, including whiplash-associated disorders (WAD). The specific objectives for study I were to assess the sex specific role of disposable income for onset and prognosis of neck pain in the general population, and if economic stress influences such potential associations. In study II the objectives were to investigate if work related physical activity and physical activity during leisure time are of importance for the risk and prognosis of neck pain. The objective of study III was to investigate if pre-treatment expectations of recovery is a prognostic factor for recovery from neck pain at seven weeks follow-up in patients seeking manual therapy treatment. And in study IV the objective was to determine if prevalent self-reported cardiovascular disorders (CVD) are associated with poor self-rated recovery in persons with WAD.

Material and methods: Study I and II were based on the Stockholm Public Health Cohort (n=23 794) with information on exposures and potential confounders collected at baseline in 2002-2003. The outcome Long Duration troublesome Neck Pain (LDNP) was measured at follow-up in 2007. Those answering “yes” to the question: “During the last five-year period, have you had neck pain for at least three consecutive months that bothered you considerably?” were classified as cases. Study III was based on the Stockholm Manual Intervention Trial (n=1057), a randomized controlled trial where patients with neck pain were studied as one cohort for the objectives of this thesis. The outcome was “recovery" measured by a modified version of the Global Perceived Recovery Question at seven weeks follow-up. Study IV was based on the Saskatchewan Government Insurance cohort including individuals who made a traffic-injury claim or received health care after a traffic injury, between 1997 and 1999. Included in study IV were 6011 participants reporting WAD. The outcome “recovery” was measured at six weeks, three months, six months, nine months, and twelve months post injury by the Global Perceived Recovery Question.

Results and conclusions: Having a low income yielded a higher odds of getting LDNP in both a cohort without neck pain at baseline (assessing risk) and a cohort with occasional neck pain at baseline (assessing prognosis), and among both sexes. Combining low income with perceived economic stress in the analyses indicates that income and economic stress interact in their association with LDNP. Higher levels of leisure physical activity than sedentary are protective of developing LDNP in a population free from neck pain at baseline. The prognosis for neck pain was not affected by leisure physical activity according to the results and physical activity within the work tasks was neither associated with risk nor prognosis of neck pain. The results from study III show that expectations of recovery is a prognostic factor for recovery from neck pain in a population seeking and receiving treatment. In study IV the results showed no associations between CVD and recovery from WAD among men and likely there is no association among women either as only weak associations were detected, and they are possibly subject to bias from residual confounding.