Mathilde G. E. Verdam

Guidelines for secondary analysis in search of response shift

ObjectiveResponse shift methods have developed substantially in the past decade, with a notable emphasis on model-based methods for response shift detection that are appropriate for the analysis of existing data sets. These secondary data analyses have yielded useful insights and motivated the continued growth of response shift methods. However, there are also challenges inherent to the successful use of secondary analysis for response shift detection. Based on our experience with a number of secondary analyses, we propose guidelines for the optimal implementation of secondary analysis for detecting response shift.MethodsWe review the definition of response shift and recent advances in response shift theory. We describe current statistical methods that have been developed for or applied to response shift detection. We then discuss lessons learned when using these methods to test specific hypotheses about response shift in existing data and of the features of a data set that could guide early decision-making about undertaking a secondary analysis.ResultsA checklist is provided that includes guidelines for secondary analyses focusing on: (1) selecting an appropriate data set to investigate response shift; (2) prerequisites of data sets and their preparation for analysis; (3) managing missing data; (4) confirming that the data fit the requirements and assumptions of the selected response shift detection technique; (5) model fit evaluation; (6) interpreting results/response shift effect sizes; and (7) comparing findings across methods.ConclusionsThe guidelines-checklist has the potential to stimulate rigorous and replicable research using existing data sets and to assist investigators in assessing the appropriateness and potential of a data set and model-based methods for response shift research.

Voluntary autonomous simulator based training in minimally invasive surgery, residents' compliance and reflection

BACKGROUND Knot tying and suturing skills in minimally invasive surgery (MIS) differ markedly from those in open surgery. Appropriate MIS training is mandatory before implementation into practice. The Advanced Suturing Course (ASC) is a structured simulator based training course that includes a 6-week autonomous training period at home on a traditional laparoscopic box trainer. Previous research did not demonstrate a significant progress in laparoscopic skills after this training period. This study aims to identify factors determining autonomous training on a laparoscopic box trainer at home. METHODS Residents (n = 97) attending 1 of 7 ASC courses between January 2009 and June 2011 were consecutively included. After 6 weeks of autonomous, training a questionnaire was completed. A random subgroup of 30 residents was requested to keep a time log. All residents received an online survey after attending the ASC. We performed outcome comparison to examine the accuracy of individual responses. RESULTS Out of 97 residents, the main motives for noncompliant autonomous training included a lack of (training) time after working hours (n = 80, 83.3%), preferred practice time during working hours (n = 76, 31.6%), or another surgical interest than MIS (n = 79, 15.2%). Previously set training goals would encourage autonomous training according to 27.8% (n = 18) of residents. Thirty participants submitted a time log and reported an average 76.5-minute weekly training time. All residents confirmed that autonomous home practice on a laparoscopic box trainer is valuable. CONCLUSIONS Autonomous practice should be structured and inclusive of adequate and sufficient feedback points. A minimally required practice time should be set. An obligatory assessment, including corresponding consequence should be conducted. Compliance herewith may result in increased voluntary (autonomous) simulator based (laparoscopic) training by residents.

Validation of a new box trainer-related tracking device: the TrEndo

BackgroundThere is an increasing demand for structured objective ex vivo training and assessment of laparoscopic psychomotor skills prior to implementation of these skills in practice. The aim of this study was to establish the internal validity of the TrEndo, a motion-tracking device, for implementation on a laparoscopic box trainer.MethodsFace validity and content validity were addressed through a structured questionnaire. To assess construct validity, participants were divided into an expert group and a novice group and performed two basic laparoscopic tasks. The TrEndo recorded five motion analysis parameters (MAPs) and time.ResultsParticipants demonstrated a high regard for face and content validity. All recorded MAPs differed significantly between experts and novices after performing a square knot. Overall, the TrEndo correctly assigned group membership in 84.7 and 95.7% of cases based on two laparoscopic tasks.ConclusionFace, content, and construct validities of the TrEndo were established. The TrEndo holds real potential as a (home) training device.

Informing relatives about their hereditary or familial cancer risk: study protocol for a randomized controlled trial

BackgroundGenetic counseling for hereditary breast or colon cancer has implications for both counselees and their relatives. Although counselees are encouraged by genetic counselors to disclose genetic cancer risk information, they do not always share this information with their at-risk relatives. Reasons for not informing relatives may be generally categorized as a lack of knowledge, motivation and/or self-efficacy. Presented here is the protocol of a randomized controlled trial that aims to establish the effectiveness of an intervention focused on supporting counselees in their disclosure of genetic cancer information to their relatives.Methods/DesignA multicenter randomized controlled trial with parallel group design will be used to compare the effects of an additional telephone counseling session performed by psychosocial workers to enhance the disclosure of genetic cancer information to at-risk relatives (intervention group) with a control group of standard care. Consecutive index patients with relatives at risk for hereditary or familial breast and/or ovarian cancer or colon cancer, are randomly assigned (block size: 8; 1:1 allocation ratio) to the intervention (n = 132) or control group (n = 132, standard care). Primary outcomes are counselees’ knowledge, motivation and self-efficacy regarding informing their relatives.DiscussionThis intervention may prove important in supporting counselees to disclose hereditary and/or familial cancer risk information to at-risk relatives and may enable more at-risk relatives to make a well-informed decision regarding genetic services and/or screening.Trial registrationThis trial is registered in the Netherlands National Trial Register (NTR) with trial ID number NTR3745.

Impact of neoadjuvant chemoradiotherapy on health-related quality of life in long-term survivors of esophageal or junctional cancer: results from the randomized CROSS trial

Background Neoadjuvant chemoradiotherapy (nCRT) plus surgery is a standard of care for patients with esophageal or junctional cancer, but the long-term impact of nCRT on health-related quality of life (HRQOL) is unknown. The purpose of this study is to compare very long-term HRQOL in long-term survivors of esophageal cancer who received nCRT plus surgery or surgery alone. Patients and methods Patients were randomly assigned to receive nCRT (carboplatin/paclitaxel with 41.4-Gy radiotherapy) plus surgery or surgery alone. HRQOL was measured using EORTC-QLQ-C30, EORTC-QLQ-OES24 and K-BILD questionnaires after a minimum follow-up of 6 years. To allow for examination over time, EORTC-QLQ-C30 and QLQ-OES24 questionnaire scores were compared with pretreatment and 12 months postoperative questionnaire scores. Physical functioning (QLQ-C30), eating problems (QLQ-OES24) and respiratory problems (K-BILD) were predefined primary end points. Predefined secondary end points were global quality of life and fatigue (both QLQ-C30). Results After a median follow-up of 105 months, 123/368 included patients (33%) were still alive (70 nCRT plus surgery, 53 surgery alone). No statistically significant or clinically relevant differential effects in HRQOL end points were found between both groups. Compared with 1-year postoperative levels, eating problems, physical functioning, global quality of life and fatigue remained at the same level in both groups. Compared with pretreatment levels, eating problems had improved (Cohens d -0.37, P = 0.011) during long-term follow-up, whereas physical functioning and fatigue were not restored to pretreatment levels in both groups (Cohens d -0.56 and 0.51, respectively, both P < 0.001). Conclusions Although physical functioning and fatigue remain reduced after long-term follow-up, no adverse impact of nCRT is apparent on long-term HRQOL compared with patients who were treated with surgery alone. In addition to the earlier reported improvement in survival and the absence of impact on short-term HRQOL, these results support the view that nCRT according to CROSS can be considered as a standard of care. Trial registration number Netherlands Trial Register NTR487.

Effect of Neoadjuvant Chemoradiotherapy on Health-Related Quality of Life in Esophageal or Junctional Cancer: Results From the Randomized CROSS Trial

Purpose To compare pre-agreed health-related quality of life (HRQOL) domains in patients with esophageal or junctional cancer who received neoadjuvant chemoradiotherapy (nCRT) followed by surgery or surgery alone. Secondary aims were to examine the effect of nCRT on HRQOL before surgery and the effect of surgery on HRQOL. Patients and Methods Patients were randomly assigned to nCRT (carboplatin plus paclitaxel with concurrent 41.4-Gy radiotherapy) followed by surgery or surgery alone. HRQOL was measured using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (QLQ-C30) and -Oesophageal Cancer Module (QLQ-OES24) questionnaires pretreatment and at 3, 6, 9, and 12 months postoperatively. The nCRT group also received preoperative questionnaires. Physical functioning (PF; QLQ-C30) and eating problems (EA; QLQ-OES24) were chosen as predefined primary end points. Predefined secondary end points were global QOL (GQOL; QLQ-C30), fatigue (FA; QLQ-C30), and emotional problems (EM; QLQ-OES24). Results A total of 363 patients were analyzed. No statistically significant differences in postoperative HRQOL were found between treatment groups. In the nCRT group, PF, EA, GQOL, FA, and EM scores deteriorated 1 week after nCRT (Cohens d: -0.93, P < .001; 0.47, P < .001; -0.84, P < .001; 1.45, P < .001; and 0.32, P = .001, respectively). In both treatment groups, all end points declined 3 months postoperatively compared with baseline (Cohens d: -1.00, 0.33, -0.47, -0.34, and 0.33, respectively; all P < .001), followed by a continuous gradual improvement. EA, GQOL, and EM were restored to baseline levels during follow-up, whereas PF and FA remained impaired 1 year postoperatively (Cohens d: 0.52 and -0.53, respectively; both P < .001). Conclusion Although HRQOL declined during nCRT, no effect of nCRT was apparent on postoperative HRQOL compared with surgery alone. In addition to the improvement in survival, these findings support the view that nCRT according to the Chemoradiotherapy for Esophageal Cancer Followed by Surgery Study-regimen can be regarded as a standard of care.

Statistical challenges of quality of life and cancer: new avenues for future research

Statistical modeling conference on the quality of life measurements of the French National Platform of Quality of Life and Cancer Faculty of Science in Luminy, Marseille, France, 12–13 September 2013 The French National Platform of Quality of Life and Cancer and the statistical team of the Mathematical Institute of Luminy undertook a successful first conference addressing the statistical challenges of measuring the quality of life in the field of oncology. More than 15 presentations were made over a 2-day period by the Faculty of Sciences in Luminy. The conference managed to assemble participants from different disciplines, such as mathematics and statistics, public health, epidemiology and psychology, to debate the key statistical and methodological issues of quality of life measurement and analysis. Three main topics were covered in this conference: the treatment of missing data, the development of item banking and computerised adaptive testing and the detection/understanding of response shift.

Open knot‐tying skills: Resident skills assessed

Open knot‐tying and suturing skills are fundamental surgical skills, founding many alternative knot‐tying techniques. It is therefore mandatory for residents to possess adequate basic open knot‐tying skills. The aim of this study was to compare an objective assessment of open knot‐tying skills by residents to a residents own estimation of his or her knot‐tying skills, before and after a knot‐tying course.

Objective versus subjective assessment of laparoscopic skill

Background. The equality of subjective- and objective-assessment methods in laparoscopic surgery are unknown. The aim of this study was to compare a subjective assessment method to an objective assessment method to evaluate laparoscopic skill. Methods. A prospective observational cohort study was conducted. Seventy-two residents completed a basic laparoscopic suturing task on a box trainer at two consecutive assessment points. Laparoscopic skill was rated subjectively using the Objective Structured Assessment of Technical Skills (OSATS) list and objectively using the TrEndo, an augmented-reality simulator. Results. TrEndo scores between the two assessment points correlated. OSATS scores did not correlate between the two assessment points. There was a correlation between TrEndo and OSATS scores at the first assessment point, but not at the second assessment point. Overall, OSATS scores correlated with TrEndo scores. There was a greater spread within OSATS scores compared to TrEndo scores. Conclusion. OSATS scores correlated with TrEndo scores. The TrEndo may be more responsive at rating individual’s laparoscopic skill, as demonstrated by a smaller overall spread in TrEndo scores. The additional value of objective assessment methods over conventional assessment methods as provided by laparoscopic simulators should be investigated.

Item bias detection in the Hospital Anxiety and Depression Scale using structural equation modeling: comparison with other item bias detection methods

PurposeComparison of patient-reported outcomes may be invalidated by the occurrence of item bias, also known as differential item functioning. We show two ways of using structural equation modeling (SEM) to detect item bias: (1) multigroup SEM, which enables the detection of both uniform and nonuniform bias, and (2) multidimensional SEM, which enables the investigation of item bias with respect to several variables simultaneously.MethodGender- and age-related bias in the items of the Hospital Anxiety and Depression Scale (HADS; Zigmond and Snaith in Acta Psychiatr Scand 67:361–370, 1983) from a sample of 1068 patients was investigated using the multigroup SEM approach and the multidimensional SEM approach. Results were compared to the results of the ordinal logistic regression, item response theory, and contingency tables methods reported by Cameron et al. (Qual Life Res 23:2883–2888, 2014).ResultsBoth SEM approaches identified two items with gender-related bias and two items with age-related bias in the Anxiety subscale, and four items with age-related bias in the Depression subscale. Results from the SEM approaches generally agreed with the results of Cameron et al., although the SEM approaches identified more items as biased.ConclusionSEM provides a flexible tool for the investigation of item bias in health-related questionnaires. Multidimensional SEM has practical and statistical advantages over multigroup SEM, and over other item bias detection methods, as it enables item bias detection with respect to multiple variables, of various measurement levels, and with more statistical power, ultimately providing more valid comparisons of patients’ well-being in both research and clinical practice.