The influence of prescribed frequency, intensity, and type of homebased exercises on exercise adherence in patients with non-specific low back pain

Abstract

Background: Low back pain is a very common disorder worldwide with a prevalence of up to 39%. Non-specific low back pain is commonly treated with exercise therapy. However, exercise adherence is low, with non-adherence of fifty to seventy percent. Several factors seem to influence exercise adherence, but the influence of frequency, intensity, and type of exercises is unknown yet. An increase in exercise adherence results in a better therapeutic effect, better quality of life, and less costs for society. Aim To determine the influence of prescribed frequency, intensity, and type of physiotherapeutic homebased exercises – separately or combined – on exercise adherence in patients with non-specific low back pain. Methods: This study had an observational longitudinal prospective cohort design. A secondary analysis of a randomized controlled trial was carried out on 185 patients with non-specific low back pain. The randomized controlled trial lasted from January 2018 to December 2019. Patients were recruited from 58 physiotherapy practices in the Netherlands and screened on eligibility. Baseline characteristics and descriptive statistics were quantified, and four linear mixed models were carried out to analyse the effect of prescribed frequency, intensity, and type of homebased exercises on exercise adherence, both separately and combined. Potential confounders were analysed as well. Results: The prescribed frequency and intensity have a significantly negative effect on the exercise adherence, both separately and combined. Frequency on itself has a coefficient of -0.31 with p<0.0005, while intensity on itself has a coefficient of -0.097 with p<0.05. The coefficients of frequency and intensity in a combined model are respectively -0.46 with p<0.0005 and -0.24 with p<0.005. Type of homebased exercise has no significantly influence on exercise adherence. Conclusion and key findings: A higher prescribed frequency and intensity of homebased exercises decrease the exercise adherence significantly in patients with non-specific low back pain, both separately and combined with other variables. However, the prescribed type of exercise has no influence on the exercise adherence in patients with non-specific low back pain. Physiotherapists should consider their prescriptions of frequency and intensity carefully when prescribing homebased exercises, if their goal is to improve exercise adherence.