Sample size, study length, and inadequate controls were the most common self-acknowledged limitations in manual therapy trials: A methodological review.

OBJECTIVES: The aim of this study was to quantify and analyze the presence and type of self-acknowledged limitations (SALs) in a sample of manual therapy (MT) randomized controlled trials. STUDY DESIGN AND SETTING: We randomly selected 120 MT trials. We extracted data related to SALs from the original reports and classified them into 12 categories. After data extraction, specific limitations within each category were identified. A descriptive analysis was performed using frequencies and percentages for qualitative variables. RESULTS: The number of SALs per trial article ranged from 0 to 8, and more than two-thirds of trials acknowledged at least two different limitations. Despite its small proportion, 9% of trials did not report SALs. The most common limitation declared, in almost half of our sample, related to sample size (47.5%) followed by limitations related to study length and follow-up (33.3%) and inadequate controls (32.5%). CONCLUSION: Our results indicate that at least two different limitations are consistently acknowledged in MT trial reports, the most common being those related to sample size, study length, follow-up, and inadequate controls. Analysis of the reasons behind the SALs gives some insights about the main difficulties in conducting research in this field and may help develop strategies to improve future research.

A methodological review revealed that reporting of trials in manual therapy has not improved over time.

OBJECTIVE: The aim of this review was to evaluate a selection of major reporting aspects in manual therapy (MT) trials, before and after the publication of the CONSORT extension for nonpharmacological trials (CONSORTnpt) STUDY DESIGN AND SETTING: We randomly selected 100 MT trials published between 2000 and 2015 and divided them into a pre-CONSORTnpt (n = 50) and a post-CONSORTnpt (n = 50) group. We extracted data on relevant issues of internal validity, reliability, and description of interventions. Two authors extracted data independently. Percentages were used for descriptive analyses, and Fisher's exact test and the chi-square test were used for group comparisons. RESULTS: Six different types of MT interventions with up to 20 controls were analyzed. The most common populations/conditions studied were healthy subjects and subjects with lower back or neck pain. Over 70% of studies included multi-session interventions, and 42% of studies reported long-term followup. The only significant differences between groups were the inclusion of a flowchart diagram, the estimated effect size, precision descriptions, and the description of intervention procedures. CONCLUSION: Our findings suggest that trials in MT show poor reporting even after the availability of standardized guidelines.