Mapping Utility Scores from a Disease-Specific Quality-of-Life Measure in Bariatric Surgery Patients

AbstractObjectivesTo develop algorithms for a conversion of disease-specific quality-of-life into health state values for morbidly obese patients before or after bariatric surgery.MethodsA total of 893 patients were enrolled in a prospective cross-sectional multicenter study. In addition to demographic and clinical data, health-related quality-of-life (HRQoL) data were collected using the disease-specific Moorehead-Ardelt II questionnaire (MA-II) and two generic questionnaires, the EuroQoL-5D (EQ-5D) and the Short Form-6D (SF-6D). Multiple regression models were constructed to predict EQ-5D- and SF-6D-based utility values from MA-II scores and additional demographic variables.ResultsThe mean body mass index was 39.4, and 591 patients (66%) had already undergone surgery. The average EQ-5D and SF-6D scores were 0.830 and 0.699. The MA-IIwas correlated to both utility measures (Spearman's r = 0.677 and 0.741). Goodness-of-fit was highest (R2 = 0.55 in the validation sample) for the following item-based transformation algorithm: utility (MA-II-based) = 0.4293 + (0.0336 × MA1) + (0.0071 × MA2) + (0.0053 × MA3) + (0.0107 × MA4) + (0.0001 × MA5). This EQ-5D-based mapping algorithm outperformed a similar SF-6D-based algorithm in terms of mean absolute percentage error (P = 0.045).ConclusionsBecause the mapping algorithm estimated utilities with only minor errors, it appears to be a valid method for calculating health state values in cost-utility analyses. The algorithm will help to define the role of bariatric surgery in morbid obesity

Reported effects in randomized controlled trials were compared with those of nonrandomized trials in cholecystectomy

Objectives: Because external validity of randomized controlled trials (RCTs) may be insufficient, the performance of nonrandomized controlled trials (nRCTs) is increasingly debated. RCTs and nRCTs were compared using the example of laparoscopic vs. open cholecystectomy (LC vs. OC). Study Design and Setting: RCTs and nRCTs comparing LC and OC were identified by searching PubMed. To assess internal and external validity of the studies, patient characteristics, relative risks, and mean differences of RCTs and nRCTs were compared by meta-analytic techniques. Results: In total, 162 studies were analyzed (136 nRCTs and 26 RCTs). Significant discrepancies between RCT- and nRCT-based results were revealed for 3 of 15 variables: overall complications (P < 0.021), wound infections (P < 0.014), and length of hospital stay (P < 0.005). In RCTs and in nRCTs, length of hospital stay and return to work were significantly reduced when using LC compared with OC. The results of nRCTs were more often heterogeneous among themselves (11 of 15) as compared with RCTs (4 of 15). Conclusion: The results of RCTs and nRCTs differ significantly in at least 20% of the variables. External validities of RCTs and nRCTs in LC vs. OC appear to be similar. Between-study heterogeneity was larger in nRCTs than in RCTs of cholecystectomy. (C) 2010 Elsevier Inc. All rights reserved

Evaluation of self-educational training methods to learn laparoscopic skills - a randomized controlled trial

Abstract Background Evaluation of two different self-educational methods (video assisted learning versus video assisted learning plus a nodal point operation primer) on learning laparoscopic suturing and intracorporal knotting. Methods Randomized controlled trial at the laparoscopic surgical training center, University of Tubingen with 45 surgical novices first year medical students being pretested for dexterity. After self-educational training for 90 min with either method (Group A: video assisted learning, Group B: video assisted learning plus a nodal point operation primer) participants had to perform five laparoscopic intracorporal knots. Assessed were number of knots completed (maximum of five knots counted, knot integrity, technical proficiency and knotting time per knot. Primary outcome measure is a composed knot score combining knot integrity, technical proficiency and knotting time. Results Group B (n = 23) achieved a significantly higher composed knot score than Group A (n = 22) (53.3 ± 8.4 versus 46.5 ± 13.6 points respectively, p = 0.016). Median knotting time per completed knot was significantly different between Group B and Group A (308 s [100–1221] versus 394 s [138–1397] respectively, p = 0.001). Concerning number of completed knots there was a trend towards more knots achieved in Group B (4.2 ± 1.2 versus 3.55 ± 1.4 respectively, p = 0.075) . Conclusions The use of a nodal point operation primer highlighting essential key steps of a procedure augment the success of learning laparoscopic skills as suturing and intracorporal knotting. (UIN researchregistry3866, March 22, 2018)