Review of Study “Vigorous Regular Leisure-Time Physical Activity Is Associated With A Clinically Important Improvement In Back Pain – A Secondary Analysis Of Randomized Controlled Trials”

Welcome back to SpineIQ’s BackBlog! This week, we will discuss a recently published study in BMC Musculoskeletal Disorders titled “Vigorous regular leisure-time physical activity is associated with a clinically important improvement in back pain – a secondary analysis of randomized controlled trials.”¹ This study was a secondary analysis of two previously completed randomized controlled trials. Along with a clinically relevant purpose and results, this study will allow us to explain some commonly used research methods that will help you feel more comfortable analyzing research independently.

Purpose

Physical activity has known beneficial effects on many different health outcomes.² However, whether doing more physical activity increases your likelihood of recovering from back or neck pain has conflicting evidence.³ This study was conducted in an attempt to assess the association between moderate and vigorous leisure time physical activity with improvement of back or neck pain.

Methods

The data of two previously completed randomized controlled trials was analyzed in this study.^4,5 Participants included in this study were adults (18-65) with neck and/or back pain that was not caused by serious or sinister pathology (e.g., cancer, trauma, cauda equina etc.). Pain intensity and physical activity data was collected using self-report questionnaires. Physical activity was assessed by asking whether low (walking and bike riding), medium (effort where you can have a conversation), and/or high (high effort) exertion was completed: never, irregularly, once per week, twice per week, or 3 times per week. Participants were considered as meeting moderate or vigorous physical activity if they reported moderate and vigorous exertion at least once per week or vigorous exertion at least 3 times per week. The participants not meeting the aforementioned moderate and vigorous physical activity were analyzed as the control group.

Minimal clinically important improvement

Change in pain intensity was the primary outcome in this study. It is important when reading a study that we find what minimally clinically important improvement, sometimes called minimal clinical important difference, was declared. This study, it was decided based on previous literature that a change of at least 2 points in pain intensity was change that patients would find meaningful. This is important because studies can declare that the difference between interventions is statistically significant (usually p value < 0.05) but that does not tell you whether the difference in interventions is enough for patients or clinicians to notice.

Risk ratio

One of the statistical tools often reported in studies is a risk ratio. These are used to describe the association between two outcomes. A risk ratio of 1 means there is no association, >1 means that the exposed group (participants meeting moderate or vigorous physical activity in this study) has a higher likelihood than the unexposed group of meeting the outcome of interest, and <1 means that the exposed group has less likelihood than the unexposed group of meeting outcome of interest (2 point change in pain intensity in this study).

Results

This study had a population of 1,464 participants where 83-90% completed follow-ups till 12 months. The results were stratified by pain location (back and neck pain, back pain alone, or neck pain alone). There was no significant association found between a minimal clinically important improvement in neck pain and meeting moderate or vigorous physical activity levels. Participants that met vigorous physically activity levels were 83% (risk ratio: 1.83, 95% confidence interval: 1.26-2.66 more likely to achieve a minimal clinically important improvement in back pain at 12 months compared to participants who were not moderate or vigorous physically activity after adjusting for potential confounders.

Conclusion

The results of this study suggest that encouraging vigorous exertion of physical activity may lead to a higher likelihood of achieving clinically meaningful pain intensity decrease for patients with back pain. While the results were uncertain for neck pain, it is important to note that this does not mean that physical activity does not have a similar result as back pain. Instead, it means that the impact of physical activity level on neck pain intensity is unknown based on this study.

References:

1. Holm LW, Onell C, Carlseus M, et al. Vigorous regular leisure-time physical activity is associated with a clinically important improvement in back pain – a secondary analysis of randomized controlled trials. BMC Musculoskelet Disord. 2021;22(1):857. doi:10.1186/s12891-021-04727-2
2. Warburton DER, Bredin SSD. Health benefits of physical activity: a systematic review of current systematic reviews. Curr Opin Cardiol. 2017;32(5):541-556. doi:10.1097/HCO.0000000000000437
3. Bohman T, Alfredsson L, Hallqvist J, Vingård E, Skillgate E. The influence of self-reported leisure time physical activity and the body mass index on recovery from persistent back pain among men and women: a population-based cohort study. BMC Public Health. 2013;13(1):385. doi:10.1186/1471-2458-13-385
4. Skillgate E, Vingård E, Alfredsson L. Naprapathic Manual Therapy or Evidence-based Care for Back and Neck Pain: A Randomized, Controlled Trial. Clin J Pain. 2007;23(5):431-439. doi:10.1097/AJP.0b013e31805593d8
5. Paanalahti K, Holm LW, Nordin M, et al. Three combinations of manual therapy techniques within naprapathy in the treatment of neck and/or back pain: a randomized controlled trial. BMC Musculoskelet Disord. 2016;17(1):176. doi:10.1186/s12891-016-1030-y