Editorial: When to Trust a Meta-analysis or Systematic Review About a Surgical Treatment, and Why

Importance of well-designed meta-analyses in assessing medical and surgical treatments

When evaluating the efficacy of medical or surgical treatments, the most robust study design is often considered to be the high-quality randomized clinical trial (RCT). However, the true answer lies in the meta-analysis of high-quality RCTs. While RCTs have their merits, meta-analyses possess two crucial qualities that make them superior: Generalizability and the ability to verify replicability across different trials. A well-designed meta-analysis, defined here as a systematic review that pools data, holds significant advantages over individual RCTs. Retrospective and observational surgical research is prone to biases that are not mutually offsetting; instead, they accumulate. Selection bias, transfer bias, and assessment bias all taint retrospective studies more than randomized trials, making the novel treatment appear more effective than it truly is. Pooling studies suffering from these limitations in a meta-analysis amplifies these biases, causing an overestimation of treatment benefits. This becomes particularly concerning when the treatment itself carries substantial risks, as is often the case in surgical journals. The consequences can result in harm or even death for patients. While a well-designed meta-analysis is the best tool for assessing medical and surgical treatments, a weak meta-analysis amplifies biases and promotes flawed data. Thoughtful readers must become proficient in honing their methodological toolkits, delving deeper into topics like heterogeneity and publication bias. It is essential to avoid wasting time on meta-analyses drawing data from retrospective or observational research regarding surgical treatments.

Effects of Plant-Based Diets on Anthropometric and Cardiometabolic Markers in Adults: An Umbrella Review

We conducted an umbrella review to consolidate the evidence of adopting plant-based diets on anthropometric and cardiometabolic outcomes. Six electronic databases (CINAHL, EMBASE, PubMed, Scopus, the Cochrane Library, and Web of Science) were searched for systematic reviews with meta-analysis (SRMAs) published from each journal's inception until 1 October 2022. Effect sizes from SRMAs and primary studies were pooled separately using random effects models. Overlapping primary studies were removed for primary studies' analyses. Seven SRMAs representing 51 primary studies were included, suggesting significant benefits of plant-based diets on weight (-2.09 kg, 95% CI: -3.56, -0.62 kg, p = 0.01, I2 = 95.6%), body mass index (-0.95 kg/m2, 95% CI: -1.26, -0.63 kg/m2, p = 0.002; I2 = 45.1%), waist circumference (-2.20 cm, 95% CI: -0.08, 0.00 cm, p = 0.04; I2 = 88.4%), fasting blood glucose (-0.11 mmol/L, 95% CI: -0.13, -0.09 mmol/L, p < 0.001, I2 = 18.2%), and low-density lipoprotein cholesterol (-0.31 mmol/L, 95% CI: -0.41, -0.20 mmol/L, p < 0.001, I2 = 65.6%). Changes in high-density lipoprotein cholesterol, triglycerides, and blood pressure were not statistically significant. Generally, plant-based diets were recommended to improve anthropometry, lipid profile, and glucose metabolism. However, findings should be interpreted with caution, because most of the reviews were rated to be of low credibility of evidence and were largely based on Western eating habits and traditions, which may limit the generalizability of findings.

Prescription Patterns, Associated Factors, and Outcomes of Opioids for Operative Foot and Ankle Fractures: A Systematic Review

BACKGROUND

Pain management after foot and ankle surgery must surmount unique challenges that are not present in orthopaedic surgery performed on other parts of the body. However, disparate and inconsistent evidence makes it difficult to draw meaningful conclusions from individual studies.

QUESTIONS/PURPOSES

In this systematic review, we asked: what are (1) the patterns of opioid use or prescription (quantity, duration, incidence of persistent use), (2) factors associated with increased or decreased risk of persistent opioid use, and (3) the clinical outcomes (principally pain relief and adverse events) associated with opioid use in patients undergoing foot or ankle fracture surgery?

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for our review. We searched PubMed, Embase, Scopus, Cochrane, and Web of Science on October 15, 2021. We included studies published from 2010 to 2021 that assessed patterns of opioid use, factors associated with increased or decreased opioid use, and other outcomes associated with opioid use after foot or ankle fracture surgery (principally pain relief and adverse events). We excluded studies on pediatric populations and studies focused on acute postoperative pain where short-term opioid use (< 1 week) was a secondary outcome only. A total of 1713 articles were assessed and 18 were included. The quality of the 16 included retrospective observational studies and two randomized trials was evaluated using the Methodological Index for Non-Randomized Studies criteria and the Jadad scale, respectively; study quality was determined to be low to moderate for observational studies and good for randomized trials. Mean patient age ranged from 42 to 53 years. Fractures studied included unimalleolar, bimalleolar, trimalleolar, and pilon fractures.

RESULTS

Proportions of postoperative persistent opioid use (defined as use beyond 3 or 6 months postoperatively) ranged from 2.6% (546 of 20,992) to 18.5% (32 of 173) and reached 39% (28 of 72) when including patients with prior opioid use. Among the numerous associations reported by observational studies, two or more preoperative opioid prescriptions had the strongest overall association with increased opioid use, but this was assessed by only one study (OR 11.92 [95% confidence interval (CI) 9.16 to 13.30]; p < 0.001). Meanwhile, spinal and regional anesthesia (-13.5 to -41.1 oral morphine equivalents (OME) difference; all p < 0.01) and postoperative ketorolac use (40 OME difference; p = 0.037) were associated with decreased opioid consumption in two observational studies and a randomized trial, respectively. Three observational studies found that opioid use preoperatively was associated with a higher proportion of emergency department visits and readmission (OR 1.41 to 17.4; all p < 0.001), and opioid use at 2 weeks postoperatively was associated with slightly higher pain scores compared with nonopioid regimens (β = 0.042; p < 0.001 and Likert scale 2.5 versus 1.6; p < 0.05) in one study.

CONCLUSION

Even after noting possible inflation of the harms of opioids in this review, our findings nonetheless highlight the need for opioid prescription guidelines specific for foot and ankle surgery. In this context, surgeons should utilize short (< 1 week) opioid prescriptions, regional anesthesia, and multimodal pain management techniques, especially in patients at increased risk of prolonged opioid use.

LEVEL OF EVIDENCE

Level III, therapeutic study.