Current practice in methodology and reporting of the sample size calculation in randomised trials of hip and knee osteoarthritis: a protocol for a systematic review

Effects of relaxation therapy on maternal psychological status and infant growth following late preterm and early-term delivery: a randomized controlled trial

BACKGROUND

Maternal stress is one modifiable variable that could influence mother-infant signaling and negatively affect breastfeeding and infant growth.

OBJECTIVES

This study aimed to test the hypothesis that relaxation therapy would reduce maternal stress and improve infant growth, behavior, and breastfeeding outcomes after late preterm (LP) and early-term (ET) delivery.

METHODS

A single-blind randomized controlled trial was conducted in healthy Chinese primiparous mother-infant pairs after LP or ET delivery (34⁺⁰-37⁺⁶ gestation weeks). Mothers were randomly assigned to the intervention group (IG, listening to relaxation meditation at least once a day) or control group (CG, normal care). Primary outcomes-changes in maternal stress (perceived stress scale), anxiety (Beck Anxiety Inventory), and infant weight and length standard deviation score-were assessed at 1 wk and 8 wks postpartum. Secondary outcomes-breast milk energy and macronutrient composition, maternal breastfeeding attitudes, infant behaviors (3-d diary), and 24-hour milk intake-were assessed at 8 wks.

RESULTS

In total, 96 mother-infant pairs were recruited. There was a significantly greater reduction in maternal perceived stress (Perceived Stress Scale score) (mean difference [MD] = 2.65; 95% CI: 0.8, 4.5) and significantly greater infant weight standard deviation score gain (MD = 0.51; 95% CI: 0.2, 0.9) from 1 wk to 8 wks in the IG than those in the CG. Exploratory analyses showed a significant interaction between intervention and sex, with greater effects on weight gain in female infants. Mothers of female infants used the intervention more frequently with significantly higher milk energy observed at 8 wks.

CONCLUSIONS

The relaxation meditation tape is a simple, effective practical tool that could easily be used in clinical settings to support breastfeeding mothers after LP and ET delivery. The findings need confirmation in larger groups and in other populations.

Minimal clinically important differences in randomised clinical trials on pain management after total hip and knee arthroplasty: a systematic review

BACKGROUND

Sample size determination is essential for reliable hypothesis testing in clinical trials and should rely on adequate sample size calculations with alpha, beta, variance, and an effect size being the minimal clinically important difference (MCID). This facilitates interpretation of the clinical relevance of statistically significant results. No gold standard for MCIDs exists in postoperative pain research.

METHODS

We searched Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for English language articles on randomised trials investigating analgesic interventions after total hip or knee arthroplasty. Primary outcomes were the reported MCIDs for pain score and cumulated rescue opioid consumption. Secondary outcomes included reported sample size calculations and propensity to report statistical significance without reaching MCID. Trend analyses were conducted using statistical process control.

RESULTS

We included 570 trials. Median MCID for 0-24 h opioid consumption was 10 mg i.v. morphine equivalents for absolute reductions (interquartile range [IQR]: 6.8-14.5) and relative 40% (IQR: 30-50%). Median MCIDs for pain scores were absolute 15 mm at rest (IQR: 10-20) and 18 mm during movement (IQR: 10-20) on a 0-100 mm VAS and relative 30% (IQR: 20-30%). No trends were demonstrated for MCIDs. Adequate sample size calculations were reported in 34% of trials. In 46% of trials with statistically significant primary outcomes, the differences did not reach the predetermined MCID.

CONCLUSIONS

We provide clinician-perceived MCID estimates for rescue opioid consumption and pain scores that can be used for sample size calculations until reliable evidence-based patient-rated MCIDs emerge. Nearly half of the trials with significant findings did not reach the predetermined MCID.

Problems persist in reporting of methods and results for the WOMAC measure in hip and knee osteoarthritis trials

Purpose

The Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a commonly used outcome measure for osteoarthritis. There are different versions of the WOMAC (Likert, visual analogue or numeric scales). A previous review of trials published before 2010 found poor reporting and inconsistency in how the WOMAC was used. This review explores whether these problems persist.

Methods

This systematic review included randomised trials of hip and/or knee osteoarthritis published in 2016 that used the WOMAC. Data were extracted on the version used, score range, analysis and results of the WOMAC, and whether these details were clearly reported.

Results

This review included 62 trials and 41 reported the WOMAC total score. The version used and item range for the WOMAC total score were unclear in 44% (n = 18/41) and 24% (n = 10/41) of trials, respectively. The smallest total score range was 0–10 (calculated by averaging 24 items scored 0–10); the largest was 0–2400 (calculated by summing 24 items scored 0–100). All trials reported the statistical analysis methods but only 29% reported the between-group mean difference and 95% confidence interval.

Conclusion

Details on the use and scoring of the WOMAC were often not reported. We recommend that trials report the version of the WOMAC and the score range used. The between-group treatment effect and corresponding confidence interval should be reported. If all the items of the WOMAC are collected, the total score and individual subscale scores should be presented. Better reporting would facilitate the interpretation, comparison and synthesis of the WOMAC score in trials.

Electronic supplementary material

The online version of this article (10.1007/s11136-018-1978-1) contains supplementary material, which is available to authorized users.