Recommendations for designing and analysing multi-arm non-inferiority trials: a review of methodology and current practice

A randomized trial of holmium laser vs thulium laser vs bipolar enucleation of large prostate glands

OBJECTIVE

To compare the outcome and morbidity of bipolar transurethral enucleation of the prostate (B-TUEP) and thulium laser enucleation of the prostate (ThuLEP) with those of holmium laser enucleation of the prostate (HoLEP) in the treatment of large symptomatic benign prostatic obstruction (BPO) through a non-inferiority randomized controlled trial (NCT03916536).

PATIENTS AND METHODS

A total of 155 patients were recruited from a single centre between February 2019 and August 2020. All had BPO, with a prostate volume ≥80 ml. Patients were randomly assigned to HoLEP, ThuLEP or B-TUEP using computer-generated random tables in a 1:1:1 ratio. Participants, investigators and surgeons were blinded to group assignment until the date of the operation. Thereafter, the patients were followed up at 1, 3, 6 and 12 months. The primary outcome was maximum urinary flow rate (Qmax ) at 6 months. Secondary outcomes included assessment of other functional urinary variables, peri-operative records, and adverse events.

RESULTS

There were 138 and 120 patients available for analysis at 6 and 12 months. There was no significant difference in Qmax between the groups at 6 and 12 months (P = 0.4 and P = 0.7, respectively), and no significant difference regarding International Prostate Symptom Score (IPSS), quality of life (QoL) or postvoid residual urine volume (PVR). The median (interquartile range) prostate-specific antigen (PSA) reductions (ng/ml) were similar in the three groups at last follow-up point (4.7 [2.2-7.1]; 5.6 [2.3-9.5] and 5 [3.4-10] after HoLEP, ThuLEP and B-TUEP, respectively). Differences in enucleation time, enucleation efficiencies and auxiliary manoeuvres were statistically insignificant (P = 0.1, 0.8 and 0.07, respectively). At 1 year, patients with prostate volumes >120 ml showed significant IPSS improvement in favour of HoLEP and ThuLEP (P = 0.01). Low- and high-grade adverse effects were recorded in 31 and five cases, respectively, with no statistically significant difference between the groups.

CONCLUSIONS

We conclude that ThuLEP and B-TUEP are as safe and effective as HoLEP for the treatment of large-sized BPO. Significant PSA reductions indicate that there was effective adenoma enucleation with all three approaches. The study provides objective evidence that endoscopic enucleation of the prostate is a technique rather than energy dependent procedure.

Mastery versus invention learning: impacts on future learning of simulated procedural skills

BACKGROUND

Invention and mastery learning approaches differ in their foundational educational paradigms, proposed mechanisms of learning, and potential impacts on learning outcomes. They also differ in their resource requirements. We explored the relative effects of 'invent and problem-solve, followed by instruction' (PS-I) learning compared to mastery learning (i.e., standards-based training) on immediate post-test and Preparation for Future Learning (PFL) assessments. PFL assessments measure learners' capacity to use their existing knowledge and strategies to learn about and solve novel problems.

METHODS

In this non-inferiority trial, pre-clerkship medical students were randomized to either PS-I, Mastery Learning (ML), or instruction then practice (CON) during simulation-based training of infant lumbar puncture (LP). After a 2-week delay, participants returned to learn and complete a PFL assessment of simulated Knee Arthrocentesis. Two independent raters assessed performances with a 5-point global rating scale.

RESULTS

Based on our non-inferiority margin, analyses showed that for both the immediate post-test and the PFL assessment, the PS-I condition resulted in non-inferior outcomes relative to the ML condition. Results for the CON condition were mixed with respect to non-inferiority compared to either PS-I or ML.

CONCLUSIONS

We suggest cautiously that the PS-I approach was not inferior to the ML approach, based on skill acquisition and PFL assessment outcomes. With ML anecdotally and empirically requiring more time, greater faculty involvement, and higher costs, our findings question the preference ML has received relative to other instructional designs, especially in the healthcare simulation community. We encourage researchers to study the educational and resource impacts of instructional designs using non-inferiority designs.