Background
Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform the surgery under the supervision of a trained surgeon. This is costly, time consuming, and is of variable effectiveness. Laparoscopic surgery involves the use of instruments using a key-hole incision and is generally considered more difficult than open surgery. Training using box models (physical simulation) is an option to supplement standard laparoscopic surgical training. The impact of box model training in surgical trainees with no prior laparoscopic experience is unknown. We sought to determine whether the box model training is useful in such trainees in terms of improving technical outcomes by performing a thorough search of the medical literature for randomised clinical trials. Randomised clinical trials are commonly called randomised controlled trials and are the best study design to answer such questions. If conducted well, they provide the most accurate answer. Two review authors searched the medical literature available to May 2013 and obtained the information from the identified trials. The use of two review authors to identify studies and obtain information decreases the errors in obtaining the information. We identified and included 25 trials in the review.
Study characteristics
The trials compared box model training versus no training (16 trials; 464 participants) or versus different types of box model training (14 trials; 382 participants) (some trials and participants were included in both comparisons as the trials compared different methods of box training versus no training).
Key results
The primary outcomes investigated in this review were time taken to perform task, error score, accuracy score, and a composite (total summed) performance score. Box model training appears to decrease the time required to perform a laparoscopic task, improve the accuracy, decrease the errors, and improves the overall performance. This suggests that the box model training improves technical skills of surgical trainees with no previous experience in laparoscopic surgery. There does not appear to be any significant differences in different methods of box model training. The impact of the improved surgical skills on patients or healthcare funders in terms of improved health or decreased costs is unknown.
Quality of evidence
All but one of the trials were of high risk of bias (defects in study design that can lead to arriving at incorrect conclusions with overestimation of benefits and underestimation of harms). Furthermore, our results are prone to risks of random errors. Overall, the quality of evidence was very low.
Future research
Further well-designed trials with less risk of bias because of poor study design or because of chance are necessary.
The results of this review are threatened by both risks of systematic errors (bias) and risks of random errors (play of chance). Laparoscopic box model training appears to improve technical skills compared with no training in trainees with no previous laparoscopic experience. The impacts of this decreased time on patients and healthcare funders in terms of improved outcomes or decreased costs are unknown. There appears to be no significant differences in the improvement of technical skills between different methods of box model training. Further well-designed trials of low risk of bias and random errors are necessary. Such trials should assess the impacts of box model training on surgical skills in both the short and long term, as well as clinical outcomes when the trainee becomes competent to operate on patients.
Surgical training has traditionally been one of apprenticeship, where the surgical trainee learns to perform surgery under the supervision of a trained surgeon. This is time consuming, costly, and of variable effectiveness. Training using a box model physical simulator - either a video box or a mirrored box - is an option to supplement standard training. However, the impact of this modality on trainees with no prior laparoscopic experience is unknown.
To compare the benefits and harms of box model training versus no training, another box model, animal model, or cadaveric model training for surgical trainees with no prior laparoscopic experience.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded to May 2013.
We included all randomised clinical trials comparing box model trainers versus no training in surgical trainees with no prior laparoscopic experience. We also included trials comparing different methods of box model training.
Two authors independently identified trials and collected data. We analysed the data with both the fixed-effect and the random-effects models using Review Manager for analysis. For each outcome, we calculated the standardised mean difference (SMD) with 95% confidence intervals (CI) based on intention-to-treat analysis whenever possible.
Twenty-five trials contributed data to the quantitative synthesis in this review. All but one trial were at high risk of bias. Overall, 16 trials (464 participants) provided data for meta-analysis of box training (248 participants) versus no supplementary training (216 participants). All the 16 trials in this comparison used video trainers. Overall, 14 trials (382 participants) provided data for quantitative comparison of different methods of box training. There were no trials comparing box model training versus animal model or cadaveric model training.
Box model training versus no training: The meta-analysis showed that the time taken for task completion was significantly shorter in the box trainer group than the control group (8 trials; 249 participants; SMD -0.48 seconds; 95% CI -0.74 to -0.22). Compared with the control group, the box trainer group also had lower error score (3 trials; 69 participants; SMD -0.69; 95% CI -1.21 to -0.17), better accuracy score (3 trials; 73 participants; SMD 0.67; 95% CI 0.18 to 1.17), and better composite performance scores (SMD 0.65; 95% CI 0.42 to 0.88). Three trials reported movement distance but could not be meta-analysed as they were not in a format for meta-analysis. There was significantly lower movement distance in the box model training compared with no training in one trial, and there were no significant differences in the movement distance between the two groups in the other two trials. None of the remaining secondary outcomes such as mortality and morbidity were reported in the trials when animal models were used for assessment of training, error in movements, and trainee satisfaction.
Different methods of box training: One trial (36 participants) found significantly shorter time taken to complete the task when box training was performed using a simple cardboard box trainer compared with the standard pelvic trainer (SMD -3.79 seconds; 95% CI -4.92 to -2.65). There was no significant difference in the time taken to complete the task in the remaining three comparisons (reverse alignment versus forward alignment box training; box trainer suturing versus box trainer drills; and single incision versus multiport box model training). There were no significant differences in the error score between the two groups in any of the comparisons (box trainer suturing versus box trainer drills; single incision versus multiport box model training; Z-maze box training versus U-maze box training). The only trial that reported accuracy score found significantly higher accuracy score with Z-maze box training than U-maze box training (1 trial; 16 participants; SMD 1.55; 95% CI 0.39 to 2.71). One trial (36 participants) found significantly higher composite score with simple cardboard box trainer compared with conventional pelvic trainer (SMD 0.87; 95% CI 0.19 to 1.56). Another trial (22 participants) found significantly higher composite score with reverse alignment compared with forward alignment box training (SMD 1.82; 95% CI 0.79 to 2.84). There were no significant differences in the composite score between the intervention and control groups in any of the remaining comparisons. None of the secondary outcomes were adequately reported in the trials.