13-year Follow-up of Women With Chronic Low Back Pain in Primary Care - a Prospective Longitudinal Cohort Study

Background: Low back pain (LBP) is among the main causes of long-term sickness absence and is associated with considerable costs for both the individual and society. LBP affects 60-80% of the population and most individuals recover, while about 10-20% develop persistent pain and disability. Women have a higher risk of developing chronic LBP (CLBP) and widespread pain.

Purpose: To investigate change in body function, activity, participation and other health related factors in women with CLBP after 13 years and to identify prognostic factors for pain, activity limitation and work ability.

Methods: In the present study, all women (n = 131) who were included in the cross-sectional study in 2006 and who were followed-up after 2 years are now invited to the same study-protocol 13 years after the first examination in 2006.

The Swedish Ethical Review Authority approved the study. Dnr: 2019-01944, 2019-05-21.

Background: Low back pain (LBP) is among the main causes of long-term sickness absence and is associated with considerable costs for both the individual and society. LBP affects 60-80% of the population and most individuals recover, while about 10-20% develop persistent pain and disability. Women have a higher risk of developing chronic LBP (CLBP) and widespread pain.

How LBP develops into recurrent and or more persistent pain with disability is not fully understood. Prognostic factors for pain development, work ability and self-rated activity limitation in 1 and 2-year follow-ups of persons with CLBP who sought primary care are described. Performance on physical capacity tests (6-min walking test), limitations on self-rated activity and participation and psycho-social factors play a role in unfavorable pain and function development. However, there are patients with CLBP who have no anatomical, demographic or psychosocial explanation of their symptoms. Some people with CLBP also have widespread pain and show altered pain sensitivity as fibromyalgia.

Purpose:To investigate change in body function, activity, participation and other health related factors in women with CLBP after 13 years and to identify prognostic factors for pain, activity limitation and work ability.

Methods: In the present study, all women (n = 131) who were included in the cross-sectional study in 2006 and who were followed-up after 2 years are now invited to the same study-protocol 13 years after the first examination in 2006.

Participants will be assessed by a registered physiotherapist at one occasion. Demographic data are collected, Questions about social support, sleep quality and sleep quantity, smoking and alcohol consumption. Self-reported questionnaires, pain and function performance tests will be assessed.

Data Analysis: Descriptive analysis based on data level; mean value (standard deviation), median (25th; 75th percentile), number and proportion will be used to present the group's characteristics. For analysis of change between the first assessment and after 13 years, Wilcoxon's signed rank test will be used for continuous variables and Teckentest / McNemar's test will be used for nominal data.

Multivariable regression analysis will be performed to calculate predictors of pain intensity (VAS), number of pain locations/pain distribution, self-rated activity limitation (RMDQ) and work ability after 13 years. Independent variables will be variables at the first assessment within the domains; body function (pain intensity, pain distribution, pain sensitivity, anxiety, depression, function test and stress), activity (RMDQ) and participation (work ability), as well as other health-related factors (Health-Related Quality of Life (SF-36), Leisure Time Physical Activity Instrument, Experience of Physical Activity). Multivariable regression models will be adjusted for age, level of education and social status. P-value is set to 0.05.

Ethical approval: The Swedish Ethical Review Authority approved the study. Dnr: 2019-01944, 2019-05-21.

Expected Results: The results is expected to provide knowledge about long-term clinical course (13 years) and prognostic factors for a positive pain and function development of CLBP in women seeking primary care.

Eligibility Criteria:
Inclusion Criteria:

* All participants (n=131) included in the Cross Sectional Study in 2006

Exclusion Criteria:

* Pregnant
* Serious somatic disorders
* Serious psychiatric disorders