Clinical prediction models

Objective!#!The aim of this study was to evaluate the validity of a semiautomated volumetric approach (5DCNS+) for the detailed assessment of the fetal brain in a clinical setting.!##!Methods!#!Stored 3D volumes of > 1100 consecutive 2nd and 3rd trimester pregnancies (range 15-36 gestational weeks) were analyzed using a workflow-based volumetric approach 5DCNS+, enabling semiautomated reconstruction of diagnostic planes of the fetal central nervous system (CNS). All 3D data sets were examined for plane accuracy, the need for manual adjustment, and fetal-maternal characteristics affecting successful plane reconstruction. We also examined the potential of these standardized views to give additional information on proper gyration and sulci formation with advancing gestation.!##!Results!#!Based on our data, we were able to show that gestational age with an OR of 1.085 (95% CI 1.041-1.132) and maternal BMI with an OR of 1.022 (95% CI 1.041-1.054) only had a slight impact on the number of manual adjustments needed to reconstruct the complete volume, while maternal age and fetal position during acquisition (p = 0.260) did not have a significant effect. For the vast majority (958/1019; 94%) of volumes, using 5DCNS+ resulted in proper reconstruction of all nine diagnostic planes. In less than 1% (89/9171 planes) of volumes, the program failed to give sufficient information. 5DCNS+ was able to show the onset and changing appearance of CNS folding in a detailed and timely manner (lateral/parietooccipital sulcus formation seen in < 65% at 16-17 gestational weeks vs. 94.6% at 19 weeks).!##!Conclusions!#!The 5DCNS+ method provides a reliable algorithm to produce detailed, 3D volume-based assessments of fetal CNS integrity through a standardized reconstruction of the orthogonal diagnostic planes. The method further gives valid and reproducible information regarding ongoing cortical development retrieved from these volume sets that might aid in earlier in utero recognition of subtle structural CNS anomalies

Head-to-head comparison of prostate cancer risk calculators predicting biopsy outcome

Background: Multivariable risk calculators (RCs) predicting prostate cancer (PCa) aim to reduce unnecessary workup (e.g., MRI and biopsy) by selectively identifying those men at risk for PCa or clinically significant PCa (csPCa) (Gleason ≥7). The lack of an adequate comparison makes choosing between RCs difficult for patients, clinicians and guideline developers. We aim to perform a head-to-head comparison of seven well known RCs predicting biopsy outcome. Methods: Our study comprised 7,119 men from ten independent contemporary cohorts in Europe and Australia, who underwent prostate biopsy between 2007 and 2015. We evaluated the performance of the ERSPC RPCRC, Finne, Chun, ProstataClass, Karakiewicz, Sunnybrook, and PCPT 2.0 (HG) RCs in predicting the presence of any PCa and csPCa. Performance was assessed by discrimination, calibration and net benefit analyses. Results: A total of 3,458 (48%) PCa were detected; 1,784 (25%) men had csPCa. No particular RC stood out predicting any PCa: pooled area under the ROC-curve (AUC) ranged between 0.64 and 0.72. The ERSPC RPCRC had the highest pooled AUC 0.77 (95% CI: 0.73-0.80) when predicting csPCa. Decision curve analysis (DCA) showed limited net benefit in the detection of csPCa, but that can be improved by a simple calibration step. The main limitation is the retrospective design of the study. Conclusions: No particular RC stands out when predicting biopsy outcome on the presence of any PCa. The ERSPC RPCRC is superior in identifying those men at risk for csPCa. Net benefit analyses show that a multivariate approach before further workup is advisable.info:eu-repo/semantics/publishedVersio

Sending Out an SMS: The Impact of Automatically Enrolling Consumers Into Overdraft Alerts

Incidental charges incurred by UK consumers on their Personal Current Account (PCA) are steep, especially for small amounts of unplanned borrowing and unpaid items. A recent policy mandates major UK banks to send consumers a text message alert of impending charges, allowing them to act before they incur a charge. Using a unique, large and detailed dataset covering the transactions of 1.5 million consumers across 6 banks, and by looking at large-scale automatic enrolment exercises carried out by two major banks, we estimate the effect of automatically enrolling consumers into these alerts. We find that automatic enrolment into alerts has large effects on charges: (i) automatic enrolment into unpaid item alerts (that inform customers of retry periods) reduces charges by 21-24% and (ii) automatic enrolment into unarranged overdraft alerts reduces charges by 25%. We also estimate average treatment effects for different types of consumers, grouped by their pre-alerts level of incidental charges (rare, occasional or heavy), and find that the benefits of automatic enrolment differ markedly between types of consumers. Those who rarely incur charges can avoid as much as half of charges thanks to alerts, whereas heavy users still incur substantial charges after automatic enrolment. We find strikingly similar patterns across the two banks, for both unpaid item and unarranged overdraft charges, providing reassurance that these findings are not specific to a particular customer base or firm implementation

Improving prediction models with new markers: A comparison of updating strategies

Background: New markers hold the promise of improving risk prediction for individual patients. We aimed to compare the performance of different strategies to extend a previously developed prediction model with a new marker. Methods: Our motivating example was the extension of a risk calculator for prostate cancer with a new marker that was available in a relatively small dataset. Performance of the strategies was also investigated in simulations. Development, marker and test sets with different sample sizes originating from the same underlying population were generated. A prediction model was fitted using logistic regression in the development set, extended using the marker set and validated in the test set. Extension strategies considered were re-estimating individual regression coefficients, updating of predictions using conditional likelihood ratios (LR) and imputation of marker values in the development set and subsequently fitting a model in the combined development and marker sets. Sample sizes considered for the development and marker set were 500 and 100, 500 and 500, and 100 and 500 patients. Discriminative ability of the extended models was quantified using the concordance statistic (c-statistic) and calibration was quantified using the calibration slope. Results: All strategies led to extended models with increased discrimination (c-statistic increase from 0.75 to 0.80 in test sets). Strategies estimating a large number of parameters (re-estimation of all coefficients and updating using conditional LR) led to overfitting (calibration slope below 1). Parsimonious methods, limiting the number of coefficients to be re-estimated, or applying shrinkage after model revision, limited the amount of overfitting. Combining the development and marker set using imputation of missing marker values approach led to consistently good performing models in all scenarios. Similar results were observed in the motivating example. Conclusion: When the sample with the new marker information is small, parsimonious methods are required to prevent overfitting of a new prediction model. Combining all data with imputation of missing marker values is an attractive option, even if a relatively large marker data set is available

Explicit teaching in the operating room:Adding the why to the what

CONTEXT: Residents need their supervisors in the operating room to inform them on how to use their expertise in present and future occasions. A few studies hint at such explicit teaching behaviour, however without explaining its underlying mechanisms. Understanding and improving explicit teaching becomes more salient nowadays, as access of residents to relevant procedures is decreasing, while end-terms of training programs remain unchanged: high quality patient care. OBJECTIVES: A structured analysis of 1. The practices supervisors use for explicit teaching and 2. How supervisors introduce explicit teaching in real time during surgical procedures. METHODS: An observational qualitative collection study in which all actions of nine supervisor-resident dyads during a total hip replacement procedure were videotaped. Interactions in which supervisors explicitly or implicitly inform residents how to use their expertise now and in future occasions were included for further analysis, using the iterative inductive process of conversation analysis. RESULTS: 1. Supervisors used a basic template of if/then rules for explicit teaching, which they regularly customized by adding metaphors, motivations, and information about preference, prevalence and consequence. 2. If/then rules are introduced by supervisors to solve a (potential) problem in outcome for the present patient in reaction to local circumstances, e.g. what residents said, did or were about to do. CONCLUSIONS: If/then rules add the why to the what. Supervisors upgrade residents' insights in surgical procedures (professional vision) and teach the degree of individual freedom and variation of their expert standards for future occasions. These insights can be beneficial in improving supervisors' teaching skills

Procalcitonin to guide taking blood cultures in the intensive care unit; a cluster-randomized controlled trial

AbstractObjectivesWe aimed to study the safety and efficacy of procalcitonin in guiding blood cultures taking in critically ill patients with suspected infection.MethodsWe performed a cluster-randomized, multi-centre, single-blinded, cross-over trial. Patients suspected of infection in whom taking blood for culture was indicated were included. The participating intensive care units were stratified and randomized by treatment regimen into a control group and a procalcitonin-guided group. All patients included in this trial followed the regimen that was allocated to the intensive care unit for that period. In both groups, blood was drawn at the same moment for a procalcitonin measurement and blood cultures. In the procalcitonin-guided group, blood cultures were sent to the department of medical microbiology when the procalcitonin was >0.25 ng/mL. The main outcome was safety, expressed as mortality at day 28 and day 90.ResultsThe control group included 288 patients and the procalcitonin-guided group included 276 patients. The 28- and 90-day mortality rates in the procalcitonin-guided group were 29% (80/276) and 38% (105/276), respectively. The mortality rates in the control group were 32% (92/288) at day 28 and 40% (115/288) at day 90. The intention-to-treat analysis showed hazard ratios of 0.85 (95% CI 0.62–1.17) and 0.89 (95% CI 0.67–1.17) for 28-day and 90-day mortality, respectively. The results were deemed non-inferior because the upper limit of the 95% CI was below the margin of 1.20.ConclusionApplying procalcitonin to guide blood cultures in critically ill patients with suspected infection seems to be safe, but the benefits may be limited.Trial registrationClinicalTrials.gov identifier: ID NCT01847079. Registered on 24 April 2013, retrospectively registered

Procalcitonin to guide taking blood cultures in the intensive care unit; a cluster-randomized controlled trial

Objectives: We aimed to study the safety and efficacy of procalcitonin in guiding blood cultures taking in critically ill patients with suspected infection. Methods: We performed a cluster-randomized, multi-centre, single-blinded, cross-over trial. Patients suspected of infection in whom taking blood for culture was indicated were included. The participating intensive care units were stratified and randomized by treatment regimen into a control group and a procalcitonin-guided group. All patients included in this trial followed the regimen that was allocated to the intensive care unit for that period. In both groups, blood was drawn at the same moment for a procalcitonin measurement and blood cultures. In the procalcitonin-guided group, blood cultures were sent to the department of medical microbiology when the procalcitonin was>0.25 ng/mL. The main outcome was safety, expressed as mortality at day 28 and day 90. Results: The control group included 288 patients and the procalcitonin-guided group included 276 patients. The 28- and 90-day mortality rates in the procalcitonin-guided group were 29% (80/276) and 38% (105/276), respectively. The mortality rates in the control group were 32% (92/288) at day 28 and 40% (115/288) at day 90. The intention-to-treat analysis showed hazard ratios of 0.85 (95% CI 0.62-1.17) and 0.89 (95% CI 0.67-1.17) for 28-day and 90-day mortality, respectively. The results were deemed non-inferior because the upper limit of the 95% CI was below the margin of 1.20. Conclusion: Applying procalcitonin to guide blood cultures in critically ill patients with suspected infection seems to be safe, but the benefits may be limited. Trial registration: . ClinicalTrials.gov identifier: ID . NCT01847079. Registered on 24 April 2013, retrospectively registered

Fingerprints of Teaching Interactions:Capturing and Quantifying How Supervisor Regulate Autonomy of Residents in the Operating Room

Objective: Supervisors and residents agree that entrusted autonomy is central to learning in the Operating Room (OR), but supervisors and residents hold different opinions about entrustment: residents regularly experience that they receive insufficient autonomy while supervisors feel their guiding is not appreciated as teaching. These opinions are commonly grounded on general experiences and perceptions, instead of real-time supervisors’ regulatory behaviors as procedures unfold. To close that gap, we captured and analyzed when and to what level supervisors award or restrain autonomy during procedures. Furthermore, we constructed fingerprints, an instrument to visualize entrustment of autonomy by supervisors in the OR that allows us to reflect on regulation of autonomy and discuss teaching interactions. Design: All interactions between supervisors and residents were captured by video and transcribed. Subsequently a multistage analysis was performed: (1) the procedure was broken down into 10 steps, (2) for each step, type and frequency of strategies by supervisors to regulate autonomy were scored, (3) the scores for each step were plotted into fingerprints, and (4) fingerprints were analyzed and compared. Setting: University Medical Centre Groningen (the Netherlands). Participants: Six different supervisor-resident dyads. Results: No fingerprint was alike: timing, frequency, and type of strategy that supervisors used to regulate autonomy varied within and between procedures. Comparing fingerprints revealed that supervisors B and D displayed more overall control over their program-year 5 residents than supervisors C and E over their program-year 4 residents. Furthermore, each supervisor restrained autonomy during steps 4 to 6 but with different intensities. Conclusions: Fingerprints show a high definition view on the unique dynamics of real-time autonomy regulation in the OR. One fingerprint functions as a snapshot and serves a purpose in one-off teaching and learning. Multiple snapshots of one resident quantify autonomy development over time, while multiple snapshots of supervisors may capture best teaching practices to feed train-the-trainer programs