Placebo effects in low back pain: A systematic review and meta-analysis of the literature.

BACKGROUND AND OBJECTIVE: The current treatments of primary musculoskeletal low back pain (LBP) have a low to moderate efficacy, which might be improved by looking at the contribution of placebo effects. However, the size of true placebo effects in LBP is unknown. Therefore, a systematic review and meta-analysis were executed of randomized controlled trials investigating placebo effects in LBP. DATABASES AND DATA TREATMENT: The study protocol was registered in the international prospective register of systematic reviews Prospero (CRD42019148745). A literature search (in PubMed, Embase, The Cochrane Library, CINAHL and PsycINFO) up to 2021 February 16th yielded 2,423 studies. Two independent reviewers assessed eligibility and risk of bias. RESULTS: Eighteen studies were eligible for the systematic review and 5 for the meta-analysis. Fourteen of the 18 studies were clinical treatment studies, and 4 were experimental studies specifically assessing placebo effects. The clinical treatment studies provided varying evidence for placebo effects in chronic LBP but insufficient evidence for acute and subacute LBP. Most experimental studies investigating chronic LBP revealed significant placebo effects. The meta-analysis of 5 treatment studies investigating chronic LBP depicted a significant moderate effect size of placebo for pain intensity (SMD = 0.57) and disability (SMD = 0.52). CONCLUSIONS: This review shows a significant contribution of placebo effects to chronic LBP symptom relief in clinical and experimental conditions. The meta-analysis revealed that placebo effects can influence chronic LBP intensity and disability. However, additional studies are required for more supporting evidence and evidence for placebo effects in acute or subacute LBP. SIGNIFICANCE: This systematic review and meta-analysis provides evidence of true placebo effects in low back pain (LBP). It shows a significant contribution of placebo effects to chronic LBP symptom relief. The results highlight the importance of patient- and context-related factors in fostering treatment effects in this patient group. New studies could provide insight into the potential value of actively making use of placebo effects in clinical practice.

Effect of physical interventions on physical performance and physical activity in older patients during hospitalization: a systematic review.

BACKGROUND: To counteract decline in physical performance and physical activity in older patients during hospitalization, multiple physical interventions were developed. However, it is unknown whether these are effective in this particular population. This systematic review aimed to identify the effect of physical interventions on physical performance and physical activity in older patients during hospitalization. METHODS: The systematic search included PubMed, EMBASE, Cinahl, the Trials database of The Cochrane Library and SPORTdiscus from inception to 22 November 2017. Studies were included if the mean age of the patient cohort was 65 years and older and the effect of physical interventions on physical performance or physical activity was evaluated during hospitalization. RESULTS: Fifteen randomized controlled trials met the inclusion criteria. Overall, the effect of physical interventions on physical performance was inconsistent. Patient tailored interventions, i.e. continuously adapted to the capabilities of the patient were not found to be superior over interventions that were not. Physical activity as outcome measure was not addressed. Reporting of intensity of the interventions and adherence were frequently lacking. CONCLUSIONS: Evidence for the effect of physical interventions on physical performance in older patients during hospitalization was found uncertain. Further research on the efficacy of the intervention is needed, comparing types of intervention with detailed reporting of frequency, intensity and duration.