Increasing availability of real-world data (RWD) generated from patient care enables the generation of evidence to inform clinical decisions for subpopulations of patients and perhaps even... Show moreIncreasing availability of real-world data (RWD) generated from patient care enables the generation of evidence to inform clinical decisions for subpopulations of patients and perhaps even individuals. There is growing opportunity to identify important heterogeneity of treatment effects (HTE) in these subgroups. Thus, HTE is relevant to all with interest in patients' responses to interventions, including regulators who must make decisions about products when signals of harms arise postapproval and payers who make coverage decisions based on expected net benefit to their beneficiaries. Prior work discussed HTE in randomized studies. Here, we address methodological considerations when investigating HTE in observational studies. We propose 4 primary goals of HTE analyses and the corresponding approaches in the context of RWD: to confirm subgroup effects, to describe the magnitude of HTE, to discover clinically important subgroups, and to predict individual effects. We discuss other possible goals including exploring prognostic score- and propensity score-based treatment effects, and testing the transportability of trial results to populations different from trial participants. Finally, we outline methodological needs for enhancing real-world HTE analysis. Show less
Ruijter, B.N.; Wolterbeek, R.; Hew, M.; Reeven, M. van; Helm, D. van der; Dubbeld, J.; ... ; Hoek, B. van 2023
Background: Primary infection with or reactivation of Epstein- Barr virus (EBV) can occur after liver transplant (LT) and can lead to posttransplant lymphoproliferative disease (PTLD). In pediatric... Show moreBackground: Primary infection with or reactivation of Epstein- Barr virus (EBV) can occur after liver transplant (LT) and can lead to posttransplant lymphoproliferative disease (PTLD). In pediatric LT, an EBV-DNA viral load (EBV VL) monitoring strategy, including the reduction of immunosuppression, has led to a lower incidence of PTLD. For adult LT recipients with less primary infection and more EBV reactivation, it is unknown whether this strategy is effective. Objective: To examine the effect of an EBV VL monitoring strategy on the incidence of PTLD after LT in adults. Design: Cohort study. Setting: Two university medical centers in the Netherlands. Patients: Adult recipients of first LT in Leiden between September 2003 and January 2017 with an EBV VL monitoring strategy formed the monitoring group (M1), recipients of first LT in Rotterdam between January 2003 and January 2017 without such a strategy formed the contemporary control group (C1), and those who had transplants in Leiden between September 1992 and September 2003 or Rotterdam between 1986 and January 2003 formed the historical control groups (M0 and C0, respectively). Measurements: Influence of EBV VL monitoring on incidence of PTLD. Results: After inverse probability of treatment weighting of the 4 groups to achieve a balance among the groups for important patient characteristics, differences within hospitals between the historical and recent era in cumulative incidences & mdash; expressed as the number of events per 1000 patients measured at 5-, 10-, and 15-year follow-up & mdash;showed fewer events in the contemporary era in both centers. This difference was considerably larger in the monitoring center, whereas the 95% CI included the null value of 0 for point estimates. Limitation: Retrospective, low statistical power, and incompletely balanced groups, and non-EBV PTLD cannot be prevented. Conclusion: Monitoring EBV VL may reduce PTLD incidence after LT in adults; larger studies are warranted. Show less
McLernon, D.J.; Giardiello, D.; Calster, B. van; Wynants, L.; Geloven, N. van; Smeden, M. van; ... ; STRATOS Initiative 2022
Risk prediction models need thorough validation to assess their performance. Validation of models for survival outcomes poses challenges due to the censoring of observations and the varying time... Show moreRisk prediction models need thorough validation to assess their performance. Validation of models for survival outcomes poses challenges due to the censoring of observations and the varying time horizon at which predictions can be made. This article describes measures to evaluate predictions and the potential improvement in decision making from survival models based on Cox proportional hazards regression.As a motivating case study, the authors consider the prediction of the composite outcome of recurrence or death (the "event ") in patients with breast cancer after surgery. They developed a simple Cox regression model with 3 predictors, as in the Nottingham Prognostic Index, in 2982 women (1275 events over 5 years of follow-up) and externally validated this model in 686 women (285 events over 5 years). Improvement in performance was assessed after the addition of progesterone receptor as a prognostic biomarker.The model predictions can be evaluated across the full range of observed follow-up times or for the event occurring by the end of a fixed time horizon of interest. The authors first discuss recommended statistical measures that evaluate model performance in terms of discrimination, calibration, or overall performance. Further, they evaluate the potential clinical utility of the model to support clinical decision making according to a net benefit measure. They provide SAS and R code to illustrate internal and external validation.The authors recommend the proposed set of performance measures for transparent reporting of the validity of predictions from survival models. Show less
Roozen, G.V.T.; Prins, M.L.M.; Binnendijk, R. van; Hartog, G. den; Kuiper, V.P.; Prins, C.; ... ; Roukens, A.H.E. 2022
Background: How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown.... Show moreBackground: How diagnostic strategies for suspected pulmonary embolism (PE) perform in relevant patient subgroups defined by sex, age, cancer, and previous venous thromboembolism (VTE) is unknown. Purpose: To evaluate the safety and efficiency of the Wells and revised Geneva scores combined with fixed and adapted D-dimer thresholds, as well as the YEARS algorithm, for ruling out acute PE in these subgroups. Data Sources: MEDLINE from 1 January 1995 until 1 January 2021. Study Selection: 16 studies assessing at least 1 diagnostic strategy. Data Extraction: Individual-patient data from 20553 patients. Data Synthesis: Safety was defined as the diagnostic failure rate (the predicted 3-month VTE incidence after exclusion of PE without imaging at baseline). Efficiency was defined as the proportion of individuals classified by the strategy as "PE con -sidered excluded" without imaging tests. Across all strategies, efficiency was highest in patients younger than 40 years (47% to 68%) and lowest in patients aged 80 years or older (6.0% to 23%) or patients with cancer (9.6% to 26%). However, efficiency improved considerably in these subgroups when pretest probabil-ity-dependent D-dimer thresholds were applied. Predicted failure rates were highest for strategies with adapted D-dimer thresh-olds, with failure rates varying between 2% and 4% in the pre-defined patient subgroups. Limitations: Between-study differences in scoring predictor items and D-dimer assays, as well as the presence of differential verifica-tion bias, in particular for classifying fatal events and subsegmental PE cases, all of which may have led to an overestimation of the predicted failure rates of adapted D-dimer thresholds. Conclusion: Overall, all strategies showed acceptable safety, with pretest probability-dependent D-dimer thresholds having not only the highest efficiency but also the highest predicted failure rate. From an efficiency perspective, this individual-patient data meta-analysis supports application of adapted D-dimer thresholds. Primary Funding Source: Dutch Research Council. (PROSPERO: CRD42018089366) Show less
Background: The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, sug-gesting a lesser severity of illness. The clinical importance of patients with... Show moreBackground: The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, sug-gesting a lesser severity of illness. The clinical importance of patients with pulmonary embolism isolated to the subseg-mental vessels is unknown.Objective: To determine the rate of recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation.Design: Multicenter prospective cohort study. (ClinicalTrials. gov: NCT01455818)Setting: Eighteen sites between February 2011 and February 2021.Patients: Patients with isolated subsegmental pulmonary embolism.Intervention: At diagnosis, patients underwent bilateral lower-extremity venous ultrasonography, which was repeated 1 week later if results were negative. Patients without deep venous thrombosis did not receive anticoagulant therapy.Measurements: The primary outcome was recurrent venous thromboembolism during the 90-day follow-up period.Results: Recruitment was stopped prematurely because the predefined stopping rule was met after 292 of a projected 300 patients were enrolled. Of the 266 patients included in the pri-mary analysis, the primary outcome occurred in 8 patients, for a cumulative incidence of 3.1% (95% CI, 1.6% to 6.1%) over the 90-day follow-up. The incidence of recurrent venous throm-boembolism was 2.1% (CI, 0.8% to 5.5%) and 5.7% (CI, 2.2% to 14.4%) over the 90-day follow-up in patients with single and multiple isolated subsegmental pulmonary embolism, respec-tively. No patients had a fatal recurrent pulmonary embolism.Limitation: The study was restricted to patients with low-risk subsegmental pulmonary embolism.Conclusion: Overall, patients with subsegmental pulmonary em-bolism who did not have proximal deep venous thrombosis had a higher-than-expected rate of recurrent venous thromboembolism. Show less
Kooij, M.K. van der; Suijkerbuijk, K.P.M.; Aarts, M.J.B.; Berkmortel, F.W.P.J. van den; Blank, C.U.; Boers-Sonderen, M.J.; ... ; Kapiteijn, E. 2021
Background: Because immune checkpoint inhibition (ICI) can cause immune-related adverse events (irAEs) mimicking immunologic diseases, patients with preexisting autoimmune disease (AID) have been... Show moreBackground: Because immune checkpoint inhibition (ICI) can cause immune-related adverse events (irAEs) mimicking immunologic diseases, patients with preexisting autoimmune disease (AID) have been excluded from clinical trials.Objective: To evaluate the safety and efficacy of ICI in patients with advanced melanoma with and without AID.Design: Nationwide cohort study.Setting: The Netherlands.Patients: 4367 patients with advanced melanoma enrolled in the Dutch Melanoma Treatment Registry (DMTR) between July 2013 and July 2018 and followed through February 2019.Measurements: Patient, clinical, and treatment characteristics; irAEs of grade 3 or higher; treatment response; and survival.Results: A total of 415 patients (9.5%) had AID, categorized as rheumatologic AID (n = 227), endocrine AID (n = 143), inflammatory bowel disease (IBD) (n = 55), or "other" (n = 8). Of these, 228 patients (55%) were treated with ICI (vs. 2546 [58%] without AID); 87 were treated with anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4), 187 with anti-programmed cell death 1 (PD-1), and 34 with the combination. The incidences of irAEs of grade 3 or higher in patients with AID were 30% (95% CI, 21% to 41%) with anti-CTLA-4, 17% (CI, 12% to 23%) with anti-PD-1, and 44% (CI, 27% to 62%) with combination therapy; for patients without AID, the incidences were 30% (CI, 27% to 33%) (n = 916), 13% (CI, 12% to 15%) (n = 1540), and 48% (CI, 43% to 53%) (n = 388), respectively. Patients with AID more often discontinued anti-PD-1 treatment because of toxicity than patients without AID (17% [CI, 12% to 23%] vs. 9% [CI, 8% to 11%]). Patients with IBD were more prone to anti-PD-1-induced colitis (6/31 = 19% [CI, 7% to 37%]) than patients with other AIDs (3% [CI, 0% to 6%]) and patients without AID (2% [CI, 2% to 3%]). The objective response rate was similar in patients with versus without AID who were treated with anti-CTLA-4 (10% [CI, 5% to 19%] vs. 16% [CI, 14% to 19%]), anti-PD-1 (40% [CI, 33% to 47%] vs. 44% [CI, 41% to 46%]), or the combination (39% [CI, 20% to 59%] vs. 43% [CI, 38% to 49%]). Survival did not differ between patients with and those without AID (median, 13 months [CI, 10 to 16 months] vs. 14 months [CI, 13 to 15 months]).Limitation: Information was limited on AID severity and immunosuppressive treatment.Conclusion: Response to ICI with anti-CTLA-4, anti-PD-1, or their combination for advanced melanoma and overall incidence of any irAEs of grade 3 or higher were similar in patients with and without preexisting AID. However, severe colitis and toxicity requiring early discontinuation of treatment occurred more frequently among patients with preexisting IBD, warranting close follow-up. Show less
Montmollin, M. de; Feller, M.; Beglinger, S.; McConnachie, A.; Aujesky, D.; Collet, T.H.; ... ; Bauer, D.C. 2020
Background: L-thyroxine does not improve hypothyroid symptoms among adults with subclinical hypothyroidism (SCH). However, those with greater symptom burden before treatment may still benefit... Show moreBackground: L-thyroxine does not improve hypothyroid symptoms among adults with subclinical hypothyroidism (SCH). However, those with greater symptom burden before treatment may still benefit.Objective: To determine whether L-thyroxine improves hypothyroid symptoms and tiredness among older adults with SCH and greater symptom burden.Design: Secondary analysis of the randomized, placebocontrolled trial TRUST (Thyroid Hormone Replacement for Untreated Older Adults with Subclinical Hypothyroidism Trial). (ClinicalTrials.gov: NCT01660126)Setting: Switzerland, Ireland, the Netherlands, and Scotland.Participants: 638 persons aged 65 years or older with persistent SCH (thyroid-stimulating hormone level of 4.60 to 19.9 mIU/L for >3 months and normal free thyroxine level) and complete outcome data.Intervention: L-thyroxine or matching placebo with mock dose titration.Measurements: 1-year change in Hypothyroid Symptoms and Tiredness scores (range, 0 to 100; higher scores indicate more symptoms) on the Thyroid-Related Quality-of-Life Patient-Reported Outcome Questionnaire among participants with high symptom burden (baseline Hypothyroid Symptoms score >30 or Tiredness score >40) versus lower symptom burden.Results: 132 participants had Hypothyroid Symptoms scores greater than 30, and 133 had Tiredness scores greater than 40. Among the group with high symptom burden, the Hypothyroid Symptoms score improved similarly between those receiving L-thyroxine (mean within-group change, -12.3 [95% CI, -16.6 to -8.0]) and those receiving placebo (mean within-group change, -10.4 [CI, -15.3 to -5.4]) at 1 year; the adjusted between-group difference was -2.0 (CI, -5.5 to 1.5; P = 0.27). Improvements in Tiredness scores were also similar between those receiving L-thyroxine (mean within-group change, -8.9 [CI, -14.5 to -3.3]) and those receiving placebo (mean within-group change, -10.9 [CI, -16.0 to -5.8]); the adjusted between-group difference was 0.0 (CI, -4.1 to 4.0; P = 0.99). There was no evidence that baseline Hypothyroid Symptoms score or Tiredness score modified the effects of L-thyroxine versus placebo (P for interaction = 0.20 and 0.82, respectively).Limitation: Post hoc analysis, small sample size, and examination of only patients with 1-year outcome data.Conclusion: In older adults with SCH and high symptom burden at baseline, L-thyroxine did not improve hypothyroid symptoms or tiredness compared with placebo. Show less
The PATH (Predictive Approaches to Treatment effect Heterogeneity) Statement was developed to promote the conduct of, and provide guidance for, predictive analyses of heterogeneity of treatment... Show moreThe PATH (Predictive Approaches to Treatment effect Heterogeneity) Statement was developed to promote the conduct of, and provide guidance for, predictive analyses of heterogeneity of treatment effects (HTE) in clinical trials. The goal of predictive HTE analysis is to provide patient-centered estimates of outcome risk with versus without the intervention, taking into account all relevant patient attributes simultaneously, to support more personalized clinical decision making than can be made on the basis of only an overall average treatment effect. The authors distinguished 2 categories of predictive HTE approaches (a "risk-modeling" and an "effect-modeling" approach) and developed 4 sets of guidance statements: criteria to determine when risk-modeling approaches are likely to identify clinically meaningful HTE, methodological aspects of risk-modeling methods, considerations for translation to clinical practice, and considerations and caveats in the use of effect-modeling approaches. They discuss limitations of these methods and enumerate research priorities for advancing methods designed to generate more personalized evidence. This explanation and elaboration document describes the intent and rationale of each recommendation and discusses related analytic considerations, caveats, and reservations. Show less
Heterogeneity of treatment effect (HTE) refers to the nonrandom variation in the magnitude or direction of a treatment effect across levels of a covariate, as measured on a selected scale, against... Show moreHeterogeneity of treatment effect (HTE) refers to the nonrandom variation in the magnitude or direction of a treatment effect across levels of a covariate, as measured on a selected scale, against a clinical outcome. In randomized controlled trials (RCTs), HTE is typically examined through a subgroup analysis that contrasts effects in groups of patients defined "1 variable at a time" (for example, male vs. female or old vs. young). The authors of this statement present guidance on an alternative approach to HTE analysis, "predictive HTE analysis." The goal of predictive HTE analysis is to provide patient-centered estimates of outcome risks with versus without the intervention, taking into account all relevant patient attributes simultaneously. The PATH (Predictive Approaches to Treatment effect Heterogeneity) Statement was developed using a multidisciplinary technical expert panel, targeted literature reviews, simulations to characterize potential problems with predictive approaches, and a deliberative process engaging the expert panel. The authors distinguish 2 categories of predictive HTE approaches: a "risk-modeling" approach, wherein a multivariable model predicts the risk for an outcome and is applied to disaggregate patients within RCTs to define risk-based variation in benefit, and an "effect-modeling" approach, wherein a model is developed on RCT data by incorporating a term for treatment assignment and interactions between treatment and baseline covariates. Both approaches can be used to predict differential absolute treatment effects, the most relevant scale for clinical decision making. The authors developed 4 sets of guidance: criteria to determine when risk-modeling approaches are likely to identify clinically important HTE, methodological aspects of risk-modeling methods, considerations for translation to clinical practice, and considerations and caveats in the use of effect-modeling approaches. The PATH Statement, together with its explanation and elaboration document, may guide future analyses and reporting of RCTs. Show less
Langenberg, M.C.C.; Hoogerwerf, M.A.; Janse, J.J.; Lieshout, L. van; Corstjens, P.L.A.M.; Roestenberg, M.; ... ; CoHSI Clinical Trial Team 2019
