The methodological quality of clinical trials of physical therapy for low back pain varies between countries with different income levels. A meta-epidemiological study.

Background: Low back pain is a severe global health problem. To face this issue, testing interventions using rigorously performed randomized controlled trials is essential. However, it is unclear if a country's income level is related to the quality of trials conducted.

Almost one in five physiotherapy trials excluded people due to lack of language proficiency: A meta-epidemiological study.

Objectives: The objective of the study was to examine the characteristics of randomized controlled trials (RCTs) evaluating physiotherapy interventions for low back pain (LBP) that specified a language-grounded eligibility criterion and the proportion of people being excluded consequently.

Study Design And Setting: This is a meta-epidemiological study of RCTs evaluating at least one type of physiotherapy intervention for treatment or prevention of LBP. Records were retrieved from Physiotherapy Evidence Database (PEDro), LILACS, and SciELO from inception to May 2021.