Does the intensity of pain and disability affect health-related quality of life of older adults with back pain? Multilevel analysis between Brazil and Netherlands: a cross-sectional study of the BACE consortium.

BACKGROUND: The prognosis of back pain (BP) in the older adults is less favorable than in younger adults and progress to adverse outcomes and consequent worsening of health-related quality of life (HRQoL). The present study aimed to verify the association between BP intensity, disability and HRQoL in older adults residents in Brazil and Netherlands, and to evaluate whether the country of residence influences the associations. METHODS: Data were collected from 602 Brazilian and 675 Dutch participants with a new episode of BP from the Back Complaints in Elders (BACE) consortium. For the present study, a cross section was used. Pain intensity and disability were assessed using the Numerical Rating Scale (NRS) and the Roland-Morris Disability Questionnaire (RMDQ), respectively. HRQoL was assessed using the Short Form Health Survey (SF-36) quality of life questionnaire. Age, sex, and education were descriptive variables. Pain intensity (NPS score) and country were the independent variables and quality of life assessed by each SF domain - 36 was the dependent variable. Analysis of models at the individual level was performed to verify the association between pain and disability, also HRQoL in Netherlands and Brazil in the total sample. The multilevel model was used to verify whether the older adults person's country of residence influenced this relationship. RESULTS: The average age of the participants was 67.00 (7.33) years. In the total sample, linear regression analysis adjusted for sex and age showed a significant association between BP intensity scores and HRQoL, for all domains. There was no association between disability and HRQoL. In the multilevel analysis, there was an association between BP intensity and HRQoL in all domains and an association between the country of residence and HRQoL, influencing the effect of pain, in all domains, except for the physical functioning. CONCLUSION: Socioeconomic and cultural aspects of different countries can affect the perception of the elderly about their HRQoL in the presence of BP. Pain and disability in Brazilian and Dutch older adults ones are experienced differently in relation to their HRQoL.