Subgroup analysis and other (mis)uses of baseline data in clinical trials

Perinatal mental health services in pregnancy and the year after birth: the ESMI research programme including RCT

Background

It is unclear how best to identify and treat women with mental disorders in pregnancy and the year after birth (i.e. the perinatal period).

Objectives

(1) To investigate how best to identify depression at antenatal booking [work package (WP) 1]. (2) To estimate the prevalence of mental disorders in early pregnancy (WP1). (3) To develop and examine the efficacy of a guided self-help intervention for mild to moderate antenatal depression delivered by psychological well-being practitioners (WP1). (4) To examine the psychometric properties of the perinatal VOICE (Views On Inpatient CarE) measure of service satisfaction (WP3). (5) To examine the clinical effectiveness and cost-effectiveness of services for women with acute severe postnatal mental disorders (WPs 1–3). (6) To investigate women’s and partners’/significant others’ experiences of different types of care (WP2).

Design

Objectives 1 and 2 – a cross-sectional survey stratified by response to Whooley depression screening questions. Objective 3 – an exploratory randomised controlled trial. Objective 4 – an exploratory factor analysis, including test–retest reliability and validity assessed by association with the Client Satisfaction Questionnaire contemporaneous satisfaction scores. Objective 5 – an observational cohort study using propensity scores for the main analysis and instrumental variable analysis using geographical distance to mother and baby unit. Objective 6 – a qualitative study.

Setting

English maternity services and generic and specialist mental health services for pregnant and postnatal women.

Participants

Staff and users of mental health and maternity services.

Interventions

Guided self-help, mother and baby units and generic care.

Main outcome measures

The following measures were evaluated in WP1(i) – specificity, sensitivity, positive predictive value, likelihood ratio, acceptability and population prevalence estimates. The following measures were evaluated in WP1(ii) – participant recruitment rate, attrition and adverse events. The following measure was evaluated in WP2 – experiences of care. The following measures were evaluated in WP3 – psychometric indices for perinatal VOICE and the proportion of participants readmitted to acute care in the year after discharge.

Results

WP1(i) – the population prevalence estimate was 11% (95% confidence interval 8% to 14%) for depression and 27% (95% confidence interval 22% to 32%) for any mental disorder in early pregnancy. The diagnostic accuracy of two depression screening questions was as follows: a weighted sensitivity of 0.41, a specificity of 0.95, a positive predictive value of 0.45, a negative predictive value of 0.93 and a likelihood ratio (positive) of 8.2. For the Edinburgh Postnatal Depression Scale, the diagnostic accuracy was as follows: a weighted sensitivity of 0.59, a specificity of 0.94, a positive predictive value of 0.52, a negative predictive value of 0.95 and a likelihood ratio (positive) of 9.8. Most women reported that asking about depression at the antenatal booking appointment was acceptable, although this was reported as being less acceptable for women with mental disorders and/or experiences of abuse. Cost-effectiveness analysis suggested that both the Whooley depression screening questions and the Edinburgh Postnatal Depression Scale were more cost-effective than with the Whooley depression screening questions followed by the Edinburgh Postnatal Depression Scale or no-screen option. WP1(ii) – 53 women with depression in pregnancy were randomised. Twenty-six women received modified guided self-help [with 18 (69%) women attending four or more sessions] and 27 women received usual care. Three women were lost to follow-up (follow-up for primary outcome: 92%). At 14 weeks post randomisation, women receiving guided self-help reported fewer depressive symptoms than women receiving usual care (adjusted effect size −0.64, 95% confidence interval −1.30 to 0.06). Costs and quality-adjusted life-years were similar, resulting in a 50% probability of guided self-help being cost-effective compared with usual care at National Institute for Health and Care Excellence cost per quality-adjusted life-year thresholds. The slow recruitment rate means that a future definitive larger trial is not feasible. WP2 – qualitative findings indicate that women valued clinicians with specialist perinatal expertise across all services, but for some women generic services were able to provide better continuity of care. Involvement of family members and care post discharge from acute services were perceived as poor across services, but there was also ambivalence among some women about increasing family involvement because of a complex range of factors. WP3(i) – for the perinatal VOICE, measures from exploratory factor analysis suggested that two factors gave an adequate fit (comparative fit index = 0.97). Items loading on these two dimensions were (1) those concerning aspects of the service relating to the care of the mother and (2) those relating to care of the baby. The factors were positively correlated (0.49; p < 0.0001). Total scores were strongly associated with service (with higher satisfaction for mother and baby units, 2 degrees of freedom; p < 0.0001) and with the ‘gold standard’ Client Service Questionnaire total score (test–retest intraclass correlation coefficient 0.784, 95% confidence interval 0.643 to 0.924; p < 0.0001). WP3(ii) – 263 of 279 women could be included in the primary analysis, which shows that the odds of being readmitted to acute care was 0.95 times higher for women who were admitted to a mother and baby unit than for those not admitted to a mother and baby unit (0.95, 95% confidence interval 0.86 to 1.04; p = 0.29). Sensitivity analysis using an instrumental variable found a markedly more significant effect of admission to mother and baby units (p < 0.001) than the primary analysis. Mother and baby units were not found to be cost-effective at 1 month post discharge because of the costs of care in a mother and baby unit. Cost-effectiveness advantages may exist if the cost of mother and baby units is offset by savings from reduced readmissions in the longer term.

Limitations

Policy and service changes had an impact on recruitment. In observational studies, residual confounding is likely.

Conclusions

Services adapted for the perinatal period are highly valued by women and may be more effective than generic services. Mother and baby units have a low probability of being cost-effective in the short term, although this may vary in the longer term.

Future work

Future work should include examination of how to reduce relapses, including in after-care following discharge, and how better to involve family members.

Trial registration

This trial is registered as ISRCTN83768230 and as study registration UKCRN ID 16403.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 10, No. 5. See the NIHR Journals Library website for further project information.

Subgroup Analysis in Pulmonary Hypertension-Specific Therapy Clinical Trials: A Systematic Review

Pulmonary hypertension (PH) treatment decisions are driven by the results of randomized controlled trials (RCTs). Subgroup analyses are often performed to assess whether the intervention effect will change due to the patient’s characteristics, thus allowing for individualized decisions. This review aimed to evaluate the appropriateness and interpretation of subgroup analyses performed in PH-specific therapy RCTs published between 2000 and 2020. Claims of subgroup effects were evaluated with prespecified criteria. Overall, 30 RCTs were included. Subgroup analyses presented: a high number of subgroup analyses reported, lack of prespecification, and lack of interaction tests. The trial protocol was not available for most RCTs; significant differences were found in those articles that published the protocol. Authors reported 13 claims of subgroup effect, with 12 claims meeting four or fewer of Sun’s criteria. Even when most RCTs were generally at low risk of bias and were published in high-impact journals, the credibility and general quality of subgroup analyses and subgroup claims were low due to methodological flaws. Clinicians should be skeptical of claims of subgroup effects and interpret subgroup analyses with caution, as due to their poor quality, these analyses may not serve as guidance for personalized care.

Multisite randomised controlled trial of trauma-focused cognitive behaviour therapy for psychosis to reduce post-traumatic stress symptoms in people with co-morbid post-traumatic stress disorder and psychosis, compared to treatment as usual: study protocol for the STAR (Study of Trauma And Recovery) trial

Background

People with psychosis have high rates of trauma, with a post-traumatic stress disorder (PTSD) prevalence rate of approximately 15%, which exacerbates psychotic symptoms such as delusions and hallucinations. Pilot studies have shown that trauma-focused (TF) psychological therapies can be safe and effective in such individuals. This trial, the largest to date, will evaluate the clinical effectiveness of a TF therapy integrated with cognitive behaviour therapy for psychosis (TF-CBTp) on post-traumatic stress symptoms in people with psychosis. The secondary aims are to compare groups on cost-effectiveness; ascertain whether TF-CBTp impacts on a range of other meaningful outcomes; determine whether therapy effects endure; and determine acceptability of the therapy in participants and therapists.

Methods

Rater-blind, parallel arm, pragmatic randomised controlled trial comparing TF-CBTp + treatment as usual (TAU) to TAU only. Adults (N = 300) with distressing post-traumatic stress and psychosis symptoms from five mental health Trusts (60 per site) will be randomised to the two groups. Therapy will be manualised, lasting 9 months (m) with trained therapists. We will assess PTSD symptom severity (primary outcome); percentage who show loss of PTSD diagnosis and clinically significant change; psychosis symptoms; emotional well-being; substance use; suicidal ideation; psychological recovery; social functioning; health-related quality of life; service use, a total of four times: before randomisation; 4 m (mid-therapy); 9 m (end of therapy; primary end point); 24 m (15 m after end of therapy) post-randomisation. Four 3-monthly phone calls will be made between 9 m and 24 m assessment points, to collect service use over the previous 3 months. Therapy acceptability will be assessed through qualitative interviews with participants (N = 35) and therapists (N = 5–10). An internal pilot will ensure integrity of trial recruitment and outcome data, as well as therapy protocol safety and adherence. Data will be analysed following intention-to-treat principles using generalised linear mixed models and reported according to Consolidated Standards of Reporting Trials-Social and Psychological Interventions Statement.

Discussion

The proposed intervention has the potential to provide significant patient benefit in terms of reductions in distressing symptoms of post-traumatic stress, psychosis, and emotional problems; enable clinicians to implement trauma-focused therapy confidently in this population; and be cost-effective compared to TAU through reduced service use.

Trial registration

ISRCTN93382525 (03/08/20)

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06215-x.

Adequate enrollment of women in cardiovascular drug trials and the need for sex-specific assessment and reporting

Cardiovascular disease (CVD) is the leading cause of death for women in the United States and globally. There is an abundance of evidence-based trials evaluating the efficacy of drug therapies to reduce morbidity and mortality in CVD. Additionally, there are well-established influences of sex, through a variety of mechanisms, on pharmacologic treatments in CVD. Despite this, the majority of drug trials are not powered to evaluate sex-specific outcomes, and much of the data that exists is gathered post hoc and through meta-analysis. The FDA established a committee in 1993 to increase the enrollment of women in clinical trials to improve this situation. Several authors, reviewing committees, and professional societies have highlighted the importance of sex-specific analysis and reporting. Despite these statements, there has not been a major improvement in representation or reporting. There are ongoing efforts to assess trial design, female representation on steering committees, and clinical trial processes to improve the representation of women. This review will describe the pharmacologic basis for the need for sex-specific assessment of cardiovascular drug therapies. It will also review the sex-specific reporting of landmark drug trials in hypertension, coronary artery disease (CAD), hyperlipidemia, and heart failure (HF). In reporting enrollment of women, several therapeutic areas like antihypertensives and newer anticoagulation trials fare better than therapeutics for HF and acute coronary syndromes. Further, drug trials and cardiometabolic or lifestyle intervention trials had a higher percentage of female participants than the device or procedural trials.

Covariate Adjustment in Cardiovascular Randomized Controlled Trials: Its Value, Current Practice, and Need for Improvement

In randomized controlled trials, patient characteristics are expected to be well balanced between treatment groups; however, adjustment for characteristics that are prognostic can still be beneficial with a modest gain in statistical power. Nevertheless, previous reviews show that many trials use unadjusted analyses. In this article, we review current practice regarding covariate adjustment in cardiovascular trials among all 84 randomized controlled trials relating to cardiovascular disease published in the New England Journal of Medicine, The Lancet, and the Journal of the American Medical Association during 2019. We identify trials in which use of covariate adjustment led to a change in the trial conclusions. By using these trials as case studies, along with data from the CHARM trial and simulation studies, we demonstrate some of the potential benefits and pitfalls of covariate adjustment. We discuss some of the complexities of using covariate adjustment, including how many covariates to choose, how covariates should be modeled, how to handle missing data for baseline covariates, and how adjusted analyses are viewed by regulators. We conclude that contemporary cardiovascular trials do not make best use of covariate adjustment and that more frequent use could lead to improvements in the efficiency of future trials.

Training for Awareness, Resilience and Action (TARA) for medical students: a single-arm mixed methods feasibility study to evaluate TARA as an indicated intervention to prevent mental disorders and stress-related symptoms

BACKGROUND

Medical students have a higher risk for depression, anxiety, stress-related symptoms, burnout, and suicide, and more rarely seek professional help or treatment than the general population. Appeals are being made to address the mental health and resilience of physicians-to-be. The novel program Training for Awareness, Resilience, and Action (TARA) was originally developed to treat depressed adolescents, targeting specific neuroscientific findings in this population. TARA has shown feasibility and preliminary efficacy in clinically depressed adolescents and corresponding brain-changes in mixed community adolescent samples. The present study investigated the feasibility and acceptability of TARA as a potential indicated prevention program for symptoms of depression, anxiety, stress and burnout in Swedish medical students.

METHODS

We conducted a single-arm trial with 23 self-selected students in their early semesters of medical school (mean age 25.38 years, 5 males and 18 females), with or without mental disorders. All participants received TARA. Self-reported symptoms of depression, anxiety, perceived stress and psychological inflexibility were collected before (T0) and after the intervention (T1). Qualitative data on the participants' experiences of TARA were collected in focus-group interviews conducted halfway through the program and upon completion of the program. Individual interviews were also conducted 2 years later. Qualitative content analysis was performed.

RESULTS

The mean attendance rate was 61.22% and the dropout rate was 17.40%. The Child Session Rating Scale administered after every session reflected an overall acceptable content, mean total score 34.99 out of 40.00. Trends towards improvement were seen across all outcome measures, including the Hospital Anxiety and Depression Scale Anxiety (t = 1.13, p = 0.29) and Depression (t = 1.71, p = 0.11) subscales, Perceived Stress Scale (t = 0.67, p = 0.51) and Avoidance and Fusion Questionnaire for youth (t = 1.64, p = 0.10). None of the participants deteriorated markedly during the intervention. Qualitative content analysis resulted in a main theme labeled: "An uncommon meeting-ground for personal empowerment", with 4 themes; "Acknowledging unmet needs", "Entering a free zone", "Feeling connected to oneself and others" and "Expanding self-efficacy".

CONCLUSION

TARA is feasible and acceptable in a mixed sample of Swedish medical students. The students' reports of entering an uncommon meeting-ground for personal empowerment supports effectiveness studies of TARA in this context.

Quantile Treatment Effect of Zinc Lozenges on Common Cold Duration: A Novel Approach to Analyze the Effect of Treatment on Illness Duration

Calculation of the difference of means is the most common approach when analyzing treatment effects on continuous outcomes. Nevertheless, it is possible that the treatment has a different effect on patients who have a lower value of the outcome compared with patients who have a greater value of the outcome. The estimation of quantile treatment effects (QTEs) allows the analysis of treatment effects over the entire distribution of a continuous outcome, such as the duration of illness or the duration of hospital stay. Furthermore, most of these outcomes have asymmetric distributions with fat tails, and censored observations are not uncommon. These features can be accounted for in the analysis of the QTE. In this paper, we use the QTE approach to analyze the effect of zinc lozenges on common cold duration. We use the data set of the Mossad (1996) trial with zinc gluconate lozenges, and three data sets of trials with zinc acetate lozenges. In the Mossad (1996) trial, zinc gluconate lozenges shortened common cold duration on average by 4.0 days (95% CI 2.3-5.7 days). However, the QTE analysis indicates that 15- to 17-day colds were shortened by 8 days, and 2-day colds by just 1 day, for the group taking zinc lozenges. Thus, the overall 4.0-day average effect of zinc gluconate lozenges in the Mossad (1996) trial is inconsistent with our QTE findings for both short and long colds. Similar results were found in our QTE analysis of the pooled data sets of the three zinc acetate lozenge trials. The average effect of 2.7 days (95% CI 1.8-3.3 days) was inconsistent with the effects on short and long colds. The QTE approach may have broad usefulness for examining treatment effects on the duration of illness and hospital stay, and on other similar outcomes.

Translational research in nephrology: prognosis

Translational research aims at reducing the gap between the results of studies focused on diagnosis, prognosis and therapy, and every day clinical practice. Prognosis is an essential component of clinical medicine. It aims at estimating the risk of adverse health outcomes in individuals, conditional to their clinical and non-clinical characteristics. There are three fundamental steps in prognostic research: development studies, in which the researcher identifies predictors, assigns the weights to each predictor, and assesses the model’s accuracy through calibration, discrimination and risk reclassification; validation studies, in which investigators test the model’s accuracy in an independent cohort of individuals; and impact studies, in which researchers evaluate whether the use of a prognostic model by clinicians improves their decision-making and patient outcome. This article aims at clarifying how to reduce the disconnection between the promises of prognostic research and the delivery of better individual health.

Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 Explanation and Elaboration: A Report of the ISPOR CHEERS II Good Practices Task Force

Health economic evaluations are comparative analyses of alternative courses of action in terms of their costs and consequences. The Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement, published in 2013, was created to ensure health economic evaluations are identifiable, interpretable, and useful for decision making. It was intended as guidance to help authors report accurately which health interventions were being compared and in what context, how the evaluation was undertaken, what the findings were, and other details that may aid readers and reviewers in interpretation and use of the study. The new CHEERS 2022 statement replaces the previous CHEERS reporting guidance. It reflects the need for guidance that can be more easily applied to all types of health economic evaluation, new methods and developments in the field, and the increased role of stakeholder involvement including patients and the public. It is also broadly applicable to any form of intervention intended to improve the health of individuals or the population, whether simple or complex, and without regard to context (such as healthcare, public health, education, and social care). This Explanation and Elaboration Report presents the new CHEERS 2022 28-item checklist with recommendations and explanation and examples for each item. The CHEERS 2022 statement is primarily intended for researchers reporting economic evaluations for peer-reviewed journals and the peer reviewers and editors assessing them for publication. Nevertheless, we anticipate familiarity with reporting requirements will be useful for analysts when planning studies. It may also be useful for health technology assessment bodies seeking guidance on reporting, given that there is an increasing emphasis on transparency in decision making.

Comparative effectiveness of ventricular tachycardia ablation vs. escalated antiarrhythmic drug therapy by location of myocardial infarction: a sub-study of the VANISH trial

AIMS

Complexity of the ventricular tachycardia (VT) substrate and the size and thickness of infarction area border zones differ based on location of myocardial infarctions (MIs). These differences may translate into heterogeneity in the effectiveness of treatments. This study aims to examine the influence of infarct location on the effectiveness of VT ablation in comparison with escalated pharmacological therapy in patients with prior MI and antiarrhythmic drug (AAD)-refractory VT.

METHODS AND RESULTS

VANISH trial participants were categorized based on the presence or absence of an inferior MI scar. Inverse probability of treatment weighted Cox models were calculated for each subgroup. Of 259 randomized patients (median age 69.8 years, 7.0% women), 135 had an inferior MI and 124 had a non-inferior MI. Among patients with an inferior MI, no statistically significant difference in the composite primary outcome of all-cause mortality, appropriate implantable cardioverter-defibrillator (ICD) shock, and VT storm was detected between treatment arms [adjusted hazard ratio (aHR) 0.80, 95% confidence interval (CI) 0.51-1.20]. In contrast, patients with non-inferior MIs had a statistically significant reduction in the incidence of the primary outcome with ablation (aHR 0.48, 95% CI 0.27-0.86). In a sensitivity analysis of anterior MI patients (n = 83), a trend towards a reduction in the primary outcome with ablation was detected (aHR 0.50, 95% CI 0.23-1.09).

CONCLUSION

The effectiveness of VT ablation versus escalated AADs varies based on the location of the MI. Patients with MI scars located only in non-inferior regions of the ventricles derive greater benefit from VT ablation in comparison to escalation of AADs in reducing VT-related events.

Groups 4 Health protects against unanticipated threats to mental health: Evaluating two interventions during COVID-19 lockdown among young people with a history of depression and loneliness

BACKGROUND

Decades of research indicate that when social connectedness is threatened, mental health is at risk. However, extant interventions to tackle loneliness have had only modest success, and none have been trialled under conditions of such threat.

METHOD

174 young people with depression and loneliness were randomised to one of two evidence-based treatments: cognitive behaviour therapy (CBT) or Groups 4 Health (G4H), an intervention designed to increase social group belonging. Depression, loneliness, and well-being outcomes were evaluated at one-year follow-up; COVID-19 lockdown restrictions were imposed partway through follow-up assessments. This provided a quasi-experimental test of the utility of each intervention in the presence (lockdown group) and absence (control group) of a threat to social connectedness.

RESULTS

At one-year follow-up, participants in lockdown reported significantly poorer wellbeing than controls who completed follow-up before lockdown, t(152)=2.41, p=.017. Although both CBT and G4H led to symptom improvement, the benefits of G4H were more robust following an unanticipated threat to social connectedness for depression (χ²(16)=31.35, p=.001), loneliness (χ²(8)=21.622, p=.006), and wellbeing (χ²(8)=22.938, p=.003).

LIMITATIONS

Because the COVID-19 lockdown was unanticipated, this analysis represents an opportunistic use of available data. As a result, we could not measure the specific impact of restrictions on participants, such as reduced income, degree of isolation, or health-related anxieties.

CONCLUSIONS

G4H delivered one year prior to COVID-19 lockdown offered greater protection than CBT against relapse of loneliness and depression symptoms. Implications are discussed with a focus on how these benefits might be extended to other life stressors and transitions.

Changes in Brain-derived Neurotrophic Factor From Active and Sham Transcranial Direct Current Stimulation in Older Adults With Knee Osteoarthritis

OBJECTIVES

Previous work has shown effects of transcranial direct current stimulation (tDCS) on clinical pain measures, qualitative sensory testing measures, and peripheral inflammation. The present report extends this research to investigate the effect of tDCS on brain-derived neurotrophic factor (BDNF) levels.

MATERIALS AND METHODS

This secondary analysis examined a sample of 40 older adults (50 to 70 y old) with symptomatic knee osteoarthritis randomly assigned in a 1:1 fashion to active (n=20) or sham (n=20) tDCS for 20 minutes on 5 consecutive days. BDNF was measured before the first session and after the final treatment session. Generalized linear modeling evaluated BDNF plasma levels as a function of tDCS group, adjusted for baseline. Bayesian statistical inference was used to quantify the probability that effects of the treatment exist.

RESULTS

Generalized linear modeling indicated a 90.4% posterior probability that the sham condition had 49.9% higher BDNF at the end of treatment, controlling for baseline. Follow-up analyses within the active TDCS group supported an association between change in BDNF and change in clinical pain, and exploratory analyses found an effect of tDCS on irisin.

DISCUSSION

Results indicated that tDCS could be a potential nonpharmacological treatment to decrease BDNF levels, which may in turn decrease pain. This study adds to a growing literature suggesting that tDCS affects cortical excitability, and consequentially, the neural circuits implicated in pain modulation. In addition to a direct connection to analgesia, BDNF changes may reflect tDCS-induced changes in different cortical areas and/or neural circuits.

Physical Exercise Improves Cognitive Function in Older Adults with Stage 3-4 Chronic Kidney Disease: A Randomized Controlled Trial

INTRODUCTION

Patients with chronic kidney disease (CKD) exhibit a higher probability of having cognitive impairment or dementia than those without CKD. The beneficial effects of physical exercise on cognitive function are known in the general older population, but more research is required in older adults with CKD.

METHODS

Eighty-one outpatients (aged ≥65 years) with CKD stage G3-G4 were assessed for eligibility. Among them, 60 were randomized (single-center, unblinded, and stratified) and 53 received the allocated intervention (exercise n = 27, control n = 26). Patients in the exercise group undertook group-exercise training at our facility once weekly and independent exercises at home twice weekly or more, for 24 weeks. Patients in the control group received general care. General and specific cognitive functions (memory, attention, executive, and verbal) were measured, and differences in their scores at baseline and at the 24-week follow-up visit were assessed between the 2 groups.

RESULTS

Forty-four patients completed the follow-up at 24 weeks (exercise n = 23, control n = 21). Patients in the exercise group showed significantly greater changes in Wechsler Memory Scale-Revised Logical Memory delayed recall (exercise effect: 2.82, 95% CI: 0.46-5.19, p = 0.03), and immediate and delayed recall (exercise effect: 5.97, 95% CI: 1.13-10.81, p = 0.02) scores than those in the control group.

CONCLUSIONS

The 24-week exercise intervention significantly improved the memory function in older adults with pre-dialysis CKD. This randomized controlled trial suggests that physical exercise is a useful nonpharmacological strategy for preventing cognitive decline in these patients.

Association of Platelet Thromboxane Inhibition by Low-Dose Aspirin With Platelet Count and Cytoreductive Therapy in Essential Thrombocythemia

Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by enhanced platelet production and thrombotic complications. The inhibition of platelet cyclooxygenase (COX) activity by the standard once‐daily aspirin is mostly incomplete due to accelerated thrombopoiesis. The phase II Aspirin Regimens in EsSential thrombocythemia (ARES) trial has recently compared the efficacy of once‐ vs. twice‐ or three‐times daily low‐dose aspirin in inhibiting platelet thromboxane (TX) A₂ production, as reflected by serum (s) TXB₂ measurements. The present substudy characterized the determinants of the highly variable response to the standard aspirin 100 mg once‐daily regimen in fully compliant patients with ET and the effects of the experimental dosing regimens on response variability. By multivariable analysis, the platelet count (directly) and cytoreductive treatment (inversely) were significantly associated with sTXB₂ values in 218 patients with ET. However, the platelet count positively correlated with sTXB₂ in patients not being treated with cytoreductive drugs (ρ = 0.51, P < 0.01, n = 84), but not in patients on cytoreduction. Patients in the lowest sTXB₂ quartile were older, more often on cytoreductive drugs, had lower platelet count and Janus‐Associated Kinase2 (JAK2)‐V617F allele frequency as compared with patients in the upper sTXB₂ quartiles. After 2 weeks of a twice‐ or 3‐times daily aspirin regimen, the association between the platelet count and sTXB₂ became similar in cytoreduced and non‐cytoreduced patients. In conclusion, the platelet count appears the strongest determinant of TXA₂ inhibition by once‐daily low‐dose aspirin in ET, with different patterns depending of cytoreductive treatment. More frequent aspirin dosing restores adequate platelet inhibition and reduces interindividual variability, independently of cytoreduction.

Targeting white matter neuroprotection as a relapse prevention strategy for treatment of cocaine use disorder: Design of a mechanism-focused randomized clinical trial

Cocaine use continues to be a significant public health problem with limited treatment options and no approved pharmacotherapies. Cognitive-behavioral therapy (CBT) remains the mainstay treatment for preventing relapse, however, people with chronic cocaine use display cognitive impairments that are associated with poor response to CBT. Emerging evidence in animal and human studies suggests that the peroxisome proliferator-activated receptor-gamma (PPAR- γ) agonist, pioglitazone, improves white matter integrity that is essential for cognitive function. This project will determine whether adjunctive use of pioglitazone enhances the effect of CBT in preventing relapse during the early phase of recovery from cocaine use disorder. This paper describes the design of a mechanism-focused phase 2 randomized clinical trial that aims first to evaluate the effects of pioglitazone on targeted mechanisms related to white matter integrity, cognitive function, and cocaine craving; and second, to evaluate the extent to which improvements on target mechanisms predict CBT response. Positive results will support pioglitazone as a potential cognitive enhancing agent to advance to later stage medication development research.

Set-regression with applications to subgroup analysis

Regression is a commonly used statistical model. It is the conditional mean of the response given covariates μ ( x ) = E ( Y | X = x ) . However, in some practical problems, the interest is the conditional mean of the response given the covariates belonging to some set A. Notably, in precision medicine and subgroup analysis in clinical trials, the aim is to identify subjects who benefit the most from the treatment, or identify an optimal set in the covariate space which manifests treatment favoritism if a subject's covariates fall in this set and the subject is classified to the favorable treatment subgroup. Existing methods for subgroup analysis achieve this indirectly by using classical regression. This motivates us to develop a new type of regression: set-regression, defined as μ ( A ) = E ( Y | X ∈ A ) which directly addresses the subgroup analysis problem. This extends not only the classical regression model but also improves recursive partitioning and support vector machine approaches, and is particularly suitable for objectives involving optimization of the regression over sets, such as subgroup analysis. We show that the new versatile set-regression identifies the subgroup with increased accuracy. It is easy to use. Simulation studies also show superior performance of the proposed method in finite samples.

Peter SD, Shanti CM, Pegoli W, Skarda D, Shilyansky J, Lemon DG, Mosquera RA, Peralta-Carcelen M, Goldstein RF, Vohr BR, Purdy IB, Hines AC, Maitre NL, Heyne RJ, DeMauro SB, McGowan EC, Yolton K, Kilbride HW, Natarajan G, Yost K, Winter S, Colaizy TT, Laughon MM, Lakshminrusimha S, Higgins RD. Initial Laparotomy Versus Peritoneal Drainage in Extremely Low Birthweight Infants With Surgical Necrotizing Enterocolitis or Isolated Intestinal Perforation: A Multicenter Randomized Clinical Trial

OBJECTIVE

The aim of this study was to determine which initial surgical treatment results in the lowest rate of death or neurodevelopmental impairment (NDI) in premature infants with necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP).

SUMMARY BACKGROUND DATA

The impact of initial laparotomy versus peritoneal drainage for NEC or IP on the rate of death or NDI in extremely low birth weight infants is unknown.

METHODS

We conducted the largest feasible randomized trial in 20 US centers, comparing initial laparotomy versus peritoneal drainage. The primary outcome was a composite of death or NDI at 18 to 22 months corrected age, analyzed using prespecified frequentist and Bayesian approaches.

RESULTS

Of 992 eligible infants, 310 were randomized and 96% had primary outcome assessed. Death or NDI occurred in 69% of infants in the laparotomy group versus 70% with drainage [adjusted relative risk (aRR) 1.0; 95% confidence interval (CI): 0.87-1.14]. A preplanned analysis identified an interaction between preoperative diagnosis and treatment group (P = 0.03). With a preoperative diagnosis of NEC, death or NDI occurred in 69% after laparotomy versus 85% with drainage (aRR 0.81; 95% CI: 0.64-1.04). The Bayesian posterior probability that laparotomy was beneficial (risk difference <0) for a preoperative diagnosis of NEC was 97%. For preoperative diagnosis of IP, death or NDI occurred in 69% after laparotomy versus 63% with drainage (aRR, 1.11; 95% CI: 0.95-1.31); Bayesian probability of benefit with laparotomy = 18%.

CONCLUSIONS

There was no overall difference in death or NDI rates at 18 to 22 months corrected age between initial laparotomy versus drainage. However, the preoperative diagnosis of NEC or IP modified the impact of initial treatment.

Posttraumatic stress symptom clusters differentially predict late positive potential to cocaine imagery cues in trauma-exposed adults with cocaine use disorder

BACKGROUND

While studies have investigated the effects of posttraumatic stress disorder (PTSD) symptoms on substance use, information on these associations in the context of drug cue reactivity is lacking, which can provide meaningful information about risk for relapse. The current study assessed the associations between PTSD symptom clusters and reactivity to cues in trauma-exposed adults with cocaine use disorder.

METHODS

We recorded electroencephalogram on 52 trauma-exposed participants (M_age = 51.3; SD = 7.0; 15.4 % women) diagnosed with cocaine use disorder while they viewed pleasant (i.e., erotic, romantic, sweet foods), unpleasant (i.e., mutilations, violence, accidents), neutral, and cocaine-related images. Reactivity was measured with the late positive potential (LPP), an indicator of motivational relevance. It was hypothesized that individuals with greater PTSD avoidance and negative alterations in cognition and mood (NACM) symptoms, as determined by the PTSD Checklist for DSM-5 (PCL-5), would have higher LPPs to cocaine-related images, indicating greater cue reactivity.

RESULTS

Linear mixed modeling indicated that higher NACM symptomatology was associated with higher LPPs to cocaine cues and higher arousal/reactivity was associated with lower LPPs to cocaine cues.

CONCLUSIONS

These results highlight the potential clinical utility of the LPP in assessing drug cue reactivity in trauma-exposed adults with substance use disorder.

Estimating heterogeneous survival treatment effect in observational data using machine learning

Methods for estimating heterogeneous treatment effect in observational data have largely focused on continuous or binary outcomes, and have been relatively less vetted with survival outcomes. Using flexible machine learning methods in the counterfactual framework is a promising approach to address challenges due to complex individual characteristics, to which treatments need to be tailored. To evaluate the operating characteristics of recent survival machine learning methods for the estimation of treatment effect heterogeneity and inform better practice, we carry out a comprehensive simulation study presenting a wide range of settings describing confounded heterogeneous survival treatment effects and varying degrees of covariate overlap. Our results suggest that the nonparametric Bayesian Additive Regression Trees within the framework of accelerated failure time model (AFT-BART-NP) consistently yields the best performance, in terms of bias, precision, and expected regret. Moreover, the credible interval estimators from AFT-BART-NP provide close to nominal frequentist coverage for the individual survival treatment effect when the covariate overlap is at least moderate. Including a nonparametrically estimated propensity score as an additional fixed covariate in the AFT-BART-NP model formulation can further improve its efficiency and frequentist coverage. Finally, we demonstrate the application of flexible causal machine learning estimators through a comprehensive case study examining the heterogeneous survival effects of two radiotherapy approaches for localized high-risk prostate cancer.

Effect of Esophageal Pressure-Guided Positive End-Expiratory Pressure on Survival from Acute Respiratory Distress Syndrome: A Risk-Based and Mechanistic Reanalysis of the EPVent-2 Trial

RATIONALE

In acute respiratory distress syndrome (ARDS), the effect of positive end-expiratory pressure (PEEP) may depend on the extent to which multiorgan dysfunction contributes to risk of death, and the precision with which PEEP is titrated to attenuate atelectrauma without exacerbating overdistension.

OBJECTIVE

To evaluate whether multiorgan dysfunction and lung mechanics modified treatment effect in EPVent-2, a multicenter trial of esophageal pressure (P_ES)-guided PEEP versus empirical high PEEP in moderate-to-severe ARDS.

METHODS

This post-hoc reanalysis of EPVent-2 evaluated for heterogeneity of treatment effect on mortality by baseline multiorgan dysfunction, determined via Acute Physiology and Chronic Health Evaluation-II (APACHE-II). It also evaluated whether PEEP titrated to end-expiratory transpulmonary pressure near 0 cmH₂O was associated with survival.

MEASUREMENTS AND MAIN RESULTS

All 200 trial participants were included. Treatment effect on 60-day mortality differed by multiorgan dysfunction severity (p=0.03 for interaction). P_ES-guided PEEP was associated with lower mortality among patients with lower APACHE-II (HR 0.43, 95% CI 0.20-0.92 for APACHE-II less than median) and may have had the opposite effect in patients with higher APACHE-II (HR 1.69; 95% CI 0.93-3.05). Independent of treatment group or multiorgan dysfunction severity, mortality was lowest when PEEP titration achieved end-expiratory transpulmonary pressure near 0 cmH₂O.

CONCLUSIONS

The effect on survival of P_ES-guided PEEP, compared to empirical high PEEP, differed by multiorgan dysfunction severity. Independent of multiorgan dysfunction, PEEP titrated to end-expiratory transpulmonary pressure closer to 0 cmH₂O was associated with greater survival than more positive or negative values. These findings warrant prospective testing in a future trial.

Pitfalls in Study Interpretation

Background: The goal of a randomized or observational study is to develop an unbiased and reliable answer to a therapeutic question. However, there are multiple pitfalls in the reporting and interpretation of data that can compromise our ability to evaluate the pragmatism and the effectiveness of the intervention being studied. Researchers must be conscious of these biases when designing their studies, just as readers must be aware of these potential pitfalls when interpreting results. Results: The purpose of this review is to highlight some of the more common sources of bias in clinical research, including internal and external validity, type 1 and type 2 error, reporting of secondary outcomes, the use of subgroup analyses, and multiple comparisons. This article also discusses potential solutions to these issues, including using the fragility index to understand the robustness of study conclusions, and generating an E value to determine the degree of unmeasured confounding in a study. Conclusions: With an understanding of these pitfalls, readers can critically review scientific literature and ascertain the validity of the conclusions.

Covariate adjustment in subgroup analyses of randomized clinical trials: A propensity score approach

BACKGROUND

Subgroup analyses are frequently conducted in randomized clinical trials to assess evidence of heterogeneous treatment effect across patient subpopulations. Although randomization balances covariates within subgroups in expectation, chance imbalance may be amplified in small subgroups and adversely impact the precision of subgroup analyses. Covariate adjustment in overall analysis of randomized clinical trial is often conducted, via either analysis of covariance or propensity score weighting, but covariate adjustment for subgroup analysis has been rarely discussed. In this article, we develop propensity score weighting methodology for covariate adjustment to improve the precision and power of subgroup analyses in randomized clinical trials.

METHODS

We extend the propensity score weighting methodology to subgroup analyses by fitting a logistic regression propensity model with pre-specified covariate-subgroup interactions. We show that, by construction, overlap weighting exactly balances the covariates with interaction terms in each subgroup. Extensive simulations were performed to compare the operating characteristics of unadjusted estimator, different propensity score weighting estimators and the analysis of covariance estimator. We apply these methods to the Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training trial to evaluate the effect of exercise training on 6-min walk test in several pre-specified subgroups.

RESULTS

Standard errors of the adjusted estimators are smaller than those of the unadjusted estimator. The propensity score weighting estimator is as efficient as analysis of covariance, and is often more efficient when subgroup sample size is small (e.g. <125), and/or when outcome model is misspecified. The weighting estimators with full-interaction propensity model consistently outperform the standard main-effect propensity model.

CONCLUSION

Propensity score weighting is a transparent and objective method to adjust chance imbalance of important covariates in subgroup analyses of randomized clinical trials. It is crucial to include the full covariate-subgroup interactions in the propensity score model.

DECRYPT trial: study protocol for a phase II randomised controlled trial of cognitive therapy for post-traumatic stress disorder (PTSD) in youth exposed to multiple traumatic stressors

BACKGROUND

Post-traumatic stress disorder (PTSD) is a distressing and disabling condition that affects significant numbers of children and adolescents. Youth exposed to multiple traumas (eg, abuse, domestic violence) are at particular risk of developing PTSD. Cognitive therapy for PTSD (CT-PTSD), derived from adult work, is a theoretically informed, disorder-specific form of trauma-focused cognitive-behavioural therapy. While efficacious for child and adolescent single-event trauma samples, its effectiveness in routine settings with more complex, multiple trauma-exposed youth has not been established. The Delivery of Cognitive Therapy for Young People after Trauma randomised controlled trial (RCT) examines the effectiveness of CT-PTSD for treating PTSD following multiple trauma exposure in children and young people in comparison with treatment as usual (TAU).

METHODS/DESIGN

This protocol describes a two-arm, patient-level, single blind, superiority RCT comparing CT-PTSD (n=60) with TAU (n=60) in children and young people aged 8-17 years with a diagnosis of PTSD following multiple trauma exposure. The primary outcome is PTSD severity assessed using the Children's Revised Impact of Event Scale (8-item version) at post-treatment (ie, approximately 5 months post-randomisation). Secondary outcomes include structured interview assessment for PTSD, complex PTSD symptoms, depression and anxiety, overall functioning and parent-rated mental health. Mid-treatment and 11-month and 29-month post-randomisation assessments will also be completed. Process-outcome evaluation will consider which mechanisms underpin or moderate recovery. Qualitative interviews with the young people, their families and their therapists will be undertaken. Cost-effectiveness of CT-PTSD relative to TAU will be also be assessed.

ETHICS AND DISSEMINATION

This trial protocol has been approved by a UK Health Research Authority Research Ethics Committee (East of England-Cambridge South, 16/EE/0233). Findings will be disseminated broadly via peer-reviewed empirical journal articles, conference presentations and clinical workshops.

TRIAL REGISTRATION

ISRCTN12077707. Registered 24 October 2016 (http://www.isrctn.com/ISRCTN12077707). Trial recruitment commenced on 1 February 2017. It is anticipated that recruitment will continue until June 2021, with 11-month assessments being concluded in May 2022.

The international ENIGMA-II substudy on postoperative cognitive disorders (ISEP)

There is a large controversy as to whether nitrous oxide (N₂O) added to the anaesthetic gas mixture is harmful or harmless for postoperative cognitive function recovery. We performed a nested study in the ENIGMA-II trial and compared postoperative neurocognitive recovery of patients randomly receiving N₂O (70%) or Air (70%) in 30% O₂ during anesthesia. We included adults having non cardiac surgery. We compared recovery scores for episodic memory, decision making/processing speed and executive functions measured with the computerised Cambridge Neuropsychological Test Automated Battery (CANTAB). Assessments were performed at baseline, seven and ninety days. At first interim analysis, following recruitment of 140 participants, the trial was suspended. We found that the mean (95%CI) changes of scores for episodic memory were in the Pocock futility boundaries. Decision making/processing speed did not differ either between groups (P > 0.182). But for executive functions at seven days, the mean number (95% CI) of problems successfully solved and the number of correct box choices made was higher in the N2O group, P = 0.029. N₂O with the limitations of an interim analysis appears to have no harmful effect on cognitive functions (memory/processing speed). It may improve the early recovery process of executive functions. This preliminary finding warrants further investigations.

Reflection on modern methods: Statistics education beyond 'significance': novel plain English interpretations to deepen understanding of statistics and to steer away from misinterpretations

Concerns have been expressed over standards of statistical interpretation. Results with P <0.05 are often referred to as 'significant' which, in plain English, implies important. This leads some people directly into the misconception that this provides proof that associations are clinically relevant. There are calls for statistics educators to respond to these concerns. This article provides novel plain English interpretations that are designed to deepen understanding. Experience teaching postgraduates at Imperial College is discussed. A key issue with focusing on 'significance' is the common inappropriate practice of implying no association exists, simply because P >0.05. Referring to strengths of association in 'study participants' gives them gravitas, which may help to avoid this. This contrasts with the common practice of focusing on imprecision, by referring to the 'sample' and to 'point estimates'. Unlike formal statistical definitions, interpretations developed and presented here are rooted in the application of statistics. They are based on one set of study participants (not many random samples). Precision of strengths of association are based on using strengths in study participants to estimate strengths of association in the population (from which participants were selected by probability random sampling). Reference to 'compatibility with study data, dependent on statistical modelling assumptions' reminds us of the importance of data quality and modelling assumptions. A straightforward graph shows the relationship between P-values and test statistics. This figure and associated interpretations were developed to illuminate the continuous nature of P-values. This is designed to discourage focus on whether P <0.05, and encourage interpretation of exact P-values.

Effect of the use of an endotracheal tube and stylet versus an endotracheal tube alone on first-attempt intubation success: a multicentre, randomised clinical trial in 999 patients

Purpose

The effect of the routine use of a stylet during tracheal intubation on first-attempt intubation success is unclear. We hypothesised that the first-attempt intubation success rate would be higher with tracheal tube + stylet than with tracheal tube alone.

Methods

In this multicentre randomised controlled trial, conducted in 32 intensive care units, we randomly assigned patients to tracheal tube + stylet or tracheal tube alone (i.e. without stylet). The primary outcome was the proportion of patients with first-attempt intubation success. The secondary outcome was the proportion of patients with complications related to tracheal intubation. Serious adverse events, i.e., traumatic injuries related to tracheal intubation, were evaluated.

Results

A total of 999 patients were included in the modified intention-to-treat analysis: 501 (50%) to tracheal tube + stylet and 498 (50%) to tracheal tube alone. First-attempt intubation success occurred in 392 patients (78.2%) in the tracheal tube + stylet group and in 356 (71.5%) in the tracheal tube alone group (absolute risk difference, 6.7; 95%CI 1.4–12.1; relative risk, 1.10; 95%CI 1.02–1.18; P = 0.01). A total of 194 patients (38.7%) in the tracheal tube + stylet group had complications related to tracheal intubation, as compared with 200 patients (40.2%) in the tracheal tube alone group (absolute risk difference, − 1.5; 95%CI − 7.5 to 4.6; relative risk, 0.96; 95%CI 0.83–1.12; P = 0.64). The incidence of serious adverse events was 4.0% and 3.6%, respectively (absolute risk difference, 0.4; 95%CI, − 2.0 to 2.8; relative risk, 1.10; 95%CI 0.59–2.06. P = 0.76).

Conclusions

Among critically ill adults undergoing tracheal intubation, using a stylet improves first-attempt intubation success.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06417-y.

Development of the Instrument to assess the Credibility of Effect Modification Analyses (ICEMAN) in randomized controlled trials and meta-analyses

BACKGROUND

Most randomized controlled trials (RCTs) and meta-analyses of RCTs examine effect modification (also called a subgroup effect or interaction), in which the effect of an intervention varies by another variable (e.g., age or disease severity). Assessing the credibility of an apparent effect modification presents challenges; therefore, we developed the Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN).

METHODS

To develop ICEMAN, we established a detailed concept; identified candidate credibility considerations in a systematic survey of the literature; together with experts, performed a consensus study to identify key considerations and develop them into instrument items; and refined the instrument based on feedback from trial investigators, systematic review authors and journal editors, who applied drafts of ICEMAN to published claims of effect modification.

RESULTS

The final instrument consists of a set of preliminary considerations, core questions (5 for RCTs, 8 for meta-analyses) with 4 response options, 1 optional item for additional considerations and a rating of credibility on a visual analogue scale ranging from very low to high. An accompanying manual provides rationales, detailed instructions and examples from the literature. Seventeen potential users tested ICEMAN; their suggestions improved the user-friendliness of the instrument.

INTERPRETATION

The Instrument for assessing the Credibility of Effect Modification Analyses offers explicit guidance for investigators, systematic reviewers, journal editors and others considering making a claim of effect modification or interpreting a claim made by others.

Paclitaxel-coated balloon angioplasty vs. drug-eluting stenting for the treatment of coronary in-stent restenosis: a comprehensive, collaborative, individual patient data meta-analysis of 10 randomized clinical trials (DAEDALUS study)

Aims

Consensus is lacking regarding the best treatment for coronary in-stent restenosis (ISR). The two most effective treatments are angioplasty with paclitaxel-coated balloon (PCB) and repeat stenting with drug-eluting stent (DES) but individual trials were not statistically powered for clinical endpoints, results were heterogeneous, and evidence about comparative efficacy and safety in relevant subsets was limited.

Methods and results

The Difference in Anti-restenotic Effectiveness of Drug-eluting stent and drug-coated balloon AngiopLasty for the occUrrence of coronary in-Stent restenosis (DAEDALUS) study was a comprehensive, investigator-initiated, collaborative, individual patient data meta-analysis comparing angioplasty with PCB alone vs. repeat stenting with DES alone for the treatment of coronary ISR. The protocol was registered with PROSPERO (CRD42017075007). All 10 available randomized clinical trials were included with 1976 patients enrolled, 1033 assigned to PCB and 943 to DES. At 3-year follow-up, PCB was associated with a significant increase in the risk of target lesion revascularization (TLR) compared with DES [hazard ratio (HR) 1.32, 95% CI 1.02–1.70, P = 0.035; number-needed-to-harm 28.5]. There was a significant interaction between treatment effect and type of restenosed stent (P = 0.029) with a more marked difference in patients with DES-ISR and comparable effects in patients with bare-metal stent-ISR. At 3-year follow-up, the primary safety endpoint of all-cause death, myocardial infarction, or target lesion thrombosis was comparable between treatments (HR 0.80, 95% CI 0.58–1.09, P = 0.152). A pre-specified subgroup analysis indicated a significant interaction between treatment effect and type of DES used to treat ISR (P = 0.033), with a lower incidence of events associated with PCB compared with first-generation DES and similar effect between PCB and second-generation DES (HR 1.06, 95% CI 0.71–1.60, P = 0.764). Long-term all-cause mortality was similar between PCB and DES (HR 0.81, 95% CI 0.53–1.22, P = 0.310); results were consistent comparing PCB and non-paclitaxel-based DES (HR 1.42, 95% CI 0.80–2.54, P = 0.235). Myocardial infarction and target lesion thrombosis were comparable between treatments.

Conclusions

In patients with coronary ISR, repeat stenting with DES is moderately more effective than angioplasty with PCB at reducing the need for TLR at 3 years. The incidence of a composite of all-cause death, myocardial infarction, or target lesion thrombosis was similar between groups. The rates of individual endpoints, including all-cause mortality, were not significantly different between groups.

Propensity score weighting for causal subgroup analysis

A common goal in comparative effectiveness research is to estimate treatment effects on prespecified subpopulations of patients. Though widely used in medical research, causal inference methods for such subgroup analysis (SGA) remain underdeveloped, particularly in observational studies. In this article, we develop a suite of analytical methods and visualization tools for causal SGA. First, we introduce the estimand of subgroup weighted average treatment effect and provide the corresponding propensity score weighting estimator. We show that balancing covariates within a subgroup bounds the bias of the estimator of subgroup causal effects. Second, we propose to use the overlap weighting (OW) method to achieve exact balance within subgroups. We further propose a method that combines OW and LASSO, to balance the bias‐variance tradeoff in SGA. Finally, we design a new diagnostic graph—the Connect‐S plot—for visualizing the subgroup covariate balance. Extensive simulation studies are presented to compare the proposed method with several existing methods. We apply the proposed methods to the patient‐centered results for uterine fibroids (COMPARE‐UF) registry data to evaluate alternative management options for uterine fibroids for relief of symptoms and quality of life.

Considerations when conducting moderation analysis with a binary outcome: Applications to clinical and social pharmacy research

Clinical and social pharmacy researchers often have questions regarding contingencies of effects (i.e., moderation) that are tested by including interactions in statistical models. Much of the available literature for estimating and testing effects that emanate from moderation models is based on extensions of the linear model with continuous outcomes. Binary (or dichotomous) outcome variables, such as prescription-medication misuse versus no misuse, are commonly encountered by clinical and social pharmacy researchers. In moderation analysis, binary outcomes have led to an increased focus on the fact that measures of interaction are scale-dependent; thus, researchers may need to consider both additive interaction and multiplicative interaction. Further complicating interpretation is that the statistical model chosen for an interaction can provide different answers to questions of moderation. This manuscript will: 1) identify research questions in clinical and social pharmacy that necessitate the use of these statistical methods, 2) review statistical models that can be used to estimate effects when the outcome of interest is binary, 3) review basic concepts of moderation, 4) describe the challenges inherent in conducting moderation analysis when modeling binary outcomes, and 5) demonstrate how to conduct such analyses and interpret relevant statistical output (including interpretations of interactions on additive and multiplicative scales with a focus on identifying which statistical models for binary outcomes lead to which measure of interaction). Although much of the basis for this paper comes from research in epidemiology, recognition of these issues has occurred in other disciplines.

Early Orthostatic Exercise by Head-Up Tilt With Stepping vs. Standard Care After Severe Traumatic Brain Injury Is Feasible

Background: Intensive rehabilitation of patients after severe traumatic brain injury aims to improve functional outcome. The effect of initiating rehabilitation in the early phase, in the form of head-up mobilization, is unclear.

Objective: To assess whether early mobilization is feasible and safe in patients with traumatic brain injury admitted to a neurointensive care unit.

Methods: This was a randomized parallel-group clinical trial, including patients with severe traumatic brain injury (Glasgow coma scale <11 and admission to the neurointensive care unit). The intervention consisted of daily mobilization on a tilt-table for 4 weeks. The control group received standard care. Outcomes were the number of included participants relative to all patients with traumatic brain injury who were approached for inclusion, the number of conducted mobilization sessions relative to all planned sessions, as well as adverse events and reactions. Information on clinical outcome was collected for exploratory purposes.

Results: Thirty-eight participants were included (19 in each group), corresponding to 76% of all approached patients [95% confidence interval (CI) 63–86%]. In the intervention group, 74% [95% CI 52–89%] of planned sessions were carried out. There was no difference in the number of adverse events, serious adverse events, or adverse reactions between the groups.

Conclusions: Early head-up mobilization is feasible in patients with severe traumatic brain injury. Larger randomized clinical trials are needed to explore potential benefits and harms of such an intervention.

Clinical Trial Registration: [ClinicalTrials.gov], identifier [NCT02924649]. Registered on 3rd October 2016.

Efficacy and Safety of Long-Term Antithrombotic Strategies in Patients With Chronic Coronary Syndrome: A Network Meta-analysis of Randomized Controlled Trials

Background Long-term antithrombotic strategies for patients with chronic coronary syndrome with high-risk factors represent an important treatment dilemma in clinical practice. Our aim was to conduct a network meta-analysis to evaluate the efficacy and safety of long-term antithrombotic strategies in patients with chronic coronary syndrome. Methods and Results Four randomized studies were included (n=75167; THEMIS [Ticagrelor on Health Outcomes in Diabetes Mellitus Patients Intervention Study], COMPASS [Cardiovascular Outcomes for People Using Anticoagulation Strategies], PEGASUS-TIMI 54 [Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54], and DAPT [Dual Anti-platelet Therapy]). The odds ratios (ORs) and 95% CIs) were calculated as the measure of effect size. The results of the network meta-analysis showed that, compared with aspirin monotherapy, the ORs for trial-defined major adverse cardiovascular and cerebrovascular events were 0.86; (95% CI, 0.80-0.93) for ticagrelor plus aspirin, 0.89 (95% CI, 0.78-1.02) for rivaroxaban monotherapy, 0.74 (95% CI, 0.64-0.85) for rivaroxaban plus aspirin, and 0.72 (95% CI, 0.60,-0.86) for thienopyridine plus aspirin. Compared with aspirin monotherapy, the ORs for trial-defined major bleeding were 2.15 (95% CI, 1.78-2.59]) for ticagrelor plus aspirin, 1.51 (95% CI, 1.23-1.85) for rivaroxaban monotherapy, and 1.68 (95% CI, 1.37-2.05) for rivaroxaban plus aspirin. For death from any cause, the improvement effect of rivaroxaban plus aspirin was detected versus aspirin monotherapy (OR, 0.76; 95% CI, 0.65-0.90), ticagrelor plus aspirin (OR, 0.79; 95% CI, 0.66-0.95), rivaroxaban monotherapy (OR, 0.82; 95% CI, 0.69-0.97), and thienopyridine plus aspirin (OR, 0.58; 95% CI, 0.41-0.82) regimens. Conclusions All antithrombotic strategies combined with aspirin significantly reduced the incidence of major adverse cardiovascular and cerebrovascular events and increased the risk of major bleeding compared with aspirin monotherapy. Considering the outcomes of all ischemic and bleeding events and all-cause mortality, rivaroxaban plus aspirin appears to be the preferred long-term antithrombotic regimen for patients with chronic coronary syndrome and high-risk factors.

Threshold-based subgroup testing in logistic regression models in two-phase sampling designs

The effect of treatment on binary disease outcome can differ across subgroups characterized by other covariates. Testing for the existence of subgroups that are associated with heterogeneous treatment effects can provide valuable insight regarding the optimal treatment recommendation in practice. Our research in this paper is motivated by the question of whether host genetics could modify a vaccine's effect on HIV acquisition risk. To answer this question, we used data from an HIV vaccine trial with a two-phase sampling design and developed a general threshold-based model framework to test for the existence of subgroups associated with the heterogeneity in disease risks, allowing for subgroups based on multivariate covariates. We developed a testing procedure based on maximum of likelihood-ratio statistics over change planes and demonstrated its advantage over alternative methods. We further developed the testing procedure to account for bias sampling of expensive (i.e. resource-intensive to measure) covariates through the incorporation of inverse probability weighting techniques. We used the proposed method to analyze the motivating HIV vaccine trial data. Our proposed testing procedure also has broad applications in epidemiological studies for assessing heterogeneity in disease risk with respect to univariate or multivariate predictors.

Effects of unsupervised behavioral and pelvic floor muscle training programs on nocturia, urinary urgency, and urinary frequency in postmenopausal women: Secondary analysis of a randomized, two-arm, parallel design, superiority trial (TULIP study)

OBJECTIVE

To determine and compare the effects of an unsupervised behavioral and pelvic floor muscle training (B-PFMT) program delivered in two formats on nocturia, urinary urgency, and urinary frequency in postmenopausal women.

STUDY DESIGN

A secondary analysis used data collected from women enrolled in the TULIP study. Women aged 55 years or more with no urinary incontinence were provided the B-PFMT program. Each woman was randomly assigned to a face-to-face class that took about 2 h (2-hrClass) or to a DVD showing essentially the same information as a 20-minute video (20-minVideo). All women were instructed to independently continue the program following their education session. Three urinary outcomes were assessed at baseline, 3, 12, and 24 months.

MAIN OUTCOME MEASURES

Nocturia and urinary urgency were examined with one item each from the questionnaire-based voiding diary, and urinary frequency was assessed with patients' self-documenting 3-day bladder diary.

RESULTS

Women in the 2-hrClass group experienced significantly fewer nocturia episodes and longer average inter-void interval at each follow-up and fewer urinary urgency episodes at 12 months. Women in the 20-minVideo group experienced significantly fewer episodes of nocturia and urinary urgency and longer average inter-void interval at each follow-up time point. No significant between-group differences were found for any outcome, except for nocturia at 24 months, when effectiveness favored women in the 20-minVideo group.

CONCLUSIONS

Unsupervised B-PFMT programs are effective for improving postmenopausal women's urinary outcomes regardless of the format. The optimal format to deliver B-PFMT programs in terms of effectiveness should be explored in future studies.

Efficacy, Safety, and Immunogenicity of Insulin Aspart Biosimilar SAR341402 Compared with Originator Insulin Aspart in Adults with Diabetes (GEMELLI 1): A Subgroup Analysis by Prior Type of Mealtime Insulin

INTRODUCTION

The biosimilar SAR341402 insulin aspart (SAR-Asp) was compared to its originator NovoLog®/NovoRapid® insulin aspart (NN-Asp) in terms of efficacy, safety, and immunogenicity, in adults with type 1 or type 2 diabetes switching from different rapid-acting insulin analogs.

METHODS

This phase 3, randomized, open-label, multinational, 52-week study (GEMELLI 1) enrolled participants with type 1 or type 2 diabetes (n = 597). At randomization, participants transitioned from NovoLog/NovoRapid (n = 380) or Humalog®/Liprolog® (n = 217) to equivalent (1:1) doses (or a dose at the discretion of the investigator) of either SAR-Asp or NN-Asp (1:1 randomization). Participants were treated with multiple daily injections in combination with insulin glargine 100 U/mL (Lantus®). In this subgroup analysis, efficacy measures (change in hemoglobin A1c [HbA1c], insulin dose [total, basal and mealtime]), and safety outcomes (hypoglycemia incidence, adverse events, anti-insulin aspart antibodies) of SAR-Asp were compared with those of NN-Asp separately according to the participants' prestudy mealtime insulin.

RESULTS

At week 26 (primary efficacy endpoint), change in HbA1c was similar between SAR-Asp and NN-Asp in those participants pre-treated with NovoLog/NovoRapid (least squares [LS] mean difference - 0.04%, 95% confidence interval [CI] - 0.182 to 0.106%) or Humalog/Liprolog (LS mean difference - 0.15%, 95% CI - 0.336 to 0.043%) (P value for treatment by subgroup interaction = 0.36). This HbA1c response persisted over the 52 weeks of the study similarly for both treatments within each subgroup. In both subgroups, changes in insulin doses were similar between treatments over 26 weeks and 52 weeks, as were the incidences of severe or any hypoglycemia, adverse events (including hypersensitivity and injection site reactions), and anti-insulin aspart antibodies.

CONCLUSIONS

Efficacy and safety (including immunogenicity) profiles of SAR-Asp are similar to those of NN-Asp over 52 weeks in adults with diabetes irrespective of prior type of mealtime insulin.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03211858.

A systematic review of subgroup analyses in randomised clinical trials in cardiovascular disease

Background:

Subgroup analyses are frequently used to assess heterogeneity of treatment effects in randomised clinical trials. Inconsistent, improper and incomplete implementation, reporting and interpretation have been identified as ongoing challenges. Further, subgroup analyses were frequently criticised because of unreliable or potentially misleading results. More recently, recommendations and guidelines have been provided to improve the reporting of data in this regard.

Methods:

This systematic review was based on a literature search within the digital archives of three selected medical journals, The New England Journal of Medicine, The Lancet and Circulation. We reviewed articles of randomised clinical trials in the domain of cardiovascular disease which were published in 2015 and 2016. We screened and evaluated the selected articles for the mode of implementation and reporting of subgroup analyses.

Results:

We were able to identify a total of 130 eligible publications of randomised clinical trials. In 89/130 (68%) articles, results of at least one subgroup analysis were presented. This was dependent on the considered journal (p < 0.001), the number of included patients (p < 0.001) and the lack of statistical significance of a trial’s primary analysis (p < 0.001). The number of reported subgroup analyses ranged from 1 to 101 (median = 13). We were able to comprehend the specification time of reported subgroup analyses for 71/89 (80%) articles, with 55/89 (62%) articles presenting exclusively pre-specified analyses. This information was not always traceable on the basis of provided trial protocols and often did not include the pre-definition of cut-off values for the categorization of subgroups. The use of interaction tests was reported in 84/89 (94%) articles, with 36/89 (40%) articles reporting heterogeneity of the treatment effect for at least one primary or secondary trial outcome. Subgroup analyses were reported more frequently for larger randomised clinical trials, and if primary analyses did not reach statistical significance. Information about the implementation of subgroup analyses was reported most consistently for articles from The New England Journal of Medicine, since it was also traceable on the basis of provided trial protocols. We were able to comprehend whether subgroup analyses were pre-specified in a majority of the reviewed publications. Even though results of multiple subgroup analyses were reported for most published trials, a corresponding adjustment for multiple testing was rarely considered.

Conclusion:

Compared to previous reviews in this context, we observed improvements in the reporting of subgroup analyses of cardiovascular randomised clinical trials. Nonetheless, critical shortcomings, such as inconsistent reporting of the implementation and insufficient pre-specification, persist.

Frequency of But Not Capacity for Participation in Everyday Activities Is Associated With Cognitive Impairment in Late Life

We examined features of everyday activities (capacity and frequency) between older adults with and without cognitive impairment over 12 months. Participants aged ≥60 years and at risk for depression were included (n = 260); 26% (n = 69) had an acquired cognitive impairment at baseline. Cognitive impairment was defined as one standard deviation below norms on the Repeatable Battery for the Assessment of Neuropsychological Status. Features of everyday activities were measured by a computerized adaptive test version of Late-Life Function and Disability Instrument (LLFDI) at six time points (baseline, 6 weeks, 3, 6, 9, 12 months). There were significant between-group differences in activity frequency (p = .04), but not activity capacity (p = .05). The group difference in activity frequency exceeded minimal detectable changes (MDC₉₀ = 3.7) and reached moderate clinical meaningfulness (∆ at six time points = 3.7-4.7). Generalized linear mixed models revealed no Group × Time interactions on activity capacity and frequency (p = .65 and p = .98). Practitioners may assess changes in activity frequency to monitor cognitive status of clients even when there is no loss of activity capacity.

Subgroup analysis in haematologic malignancies phase III clinical trials: A systematic review

AIMS

To assess the appropriateness of the use and interpretation of subgroup analysis in haematology randomized clinical trials (RCTs).

METHOD

A systematic review of Medline, including haematology phase III RCTs published between January 2013 and October 2019, was carried out to identify reported subgroup analysis. Information related to trial characteristics, subgroup analysis and claims of subgroup difference were collected.

RESULTS

The initial search identified 1622 studies. A total of 98 studies reporting subgroup analyses were identified. Of those, 24 RCT reported 46 claims of subgroup difference. Among them, 44 were claims for the primary outcome, of which 25 were considered strong claims and 17 were considered suggestions of a possible effect. Authors included subgroup variables for the primary outcome measured at baseline for 38 claims (n = 86.36%), used a subgroup variable as a stratification factor at randomization for 15 (34.09%), clearly prespecified their hypothesis for 11 (25%), the subgroup effect was one of a small number of hypothesised effects tested (≤ 5) for 17 (38.64%), carried out a test of interaction that provide statistically significant for 18 (40.91%), documented replication of a subgroup effect with previously related studies for 11 (25%), identified the consistency of a subgroup effect across related outcome for 10 (22.72%) and provided a biological rationale for the effect for 8 (18.18%). Of the 44 claims for the primary outcome, 34 (77.27%) met four or fewer of the 10 credibility criteria.

CONCLUSION

The subgroup claims reported in haematology RCTs lack credibility, even when the claims are strong. Information about subgroup difference should be interpreted cautiously.

A Review and a Framework of Variables for Defining and Characterizing Tinnitus Subphenotypes

Tinnitus patients can present with various characteristics, such as those related to the tinnitus perception, symptom severity, and pattern of comorbidities. It is speculated that this phenotypic heterogeneity is associated with differences in the underlying pathophysiology and personal reaction to the condition. However, there is as yet no established protocol for tinnitus profiling or subtyping, hindering progress in treatment development. This review summarizes data on variables that have been used in studies investigating phenotypic differences in subgroups of tinnitus, including variables used to both define and compare subgroups. A PubMed search led to the identification of 64 eligible articles. In most studies, variables for subgrouping were chosen by the researchers (hypothesis-driven approach). Other approaches included application of unsupervised machine-learning techniques for the definition of subgroups (data-driven), and subgroup definition based on the response to a tinnitus treatment (treatment response). A framework of 94 variable concepts was created to summarize variables used across all studies. Frequency statistics for the use of each variable concept are presented, demonstrating those most and least commonly assessed. This review highlights the high dimensionality of tinnitus heterogeneity. The framework of variables can contribute to the design of future studies, helping to decide on tinnitus assessment and subgrouping.

Randomised controlled trial of tailored support to increase physical activity and reduce smoking in smokers not immediately ready to quit: protocol for the Trial of physical Activity-assisted Reduction of Smoking (TARS) Study

INTRODUCTION

Smoking reduction can lead to increased success in quitting. This study aims to determine if a client-focused motivational support package for smoking reduction (and quitting) and increasing (or otherwise using) physical activity (PA) can help smokers who do not wish to quit immediately to reduce the amount they smoke, and ultimately quit. This paper reports the study design and methods.

METHODS AND ANALYSIS

A pragmatic, multicentred, parallel, two group, randomised controlled superiority clinical trial, with embedded process evaluation and economics evaluation. Participants who wished to reduce smoking with no immediate plans to quit were randomised 1:1 to receive either (1) tailored individual health trainer face-to-face and/or telephone support to reduce smoking and increase PA as an aid to smoking reduction (intervention) or (2) brief written/electronic advice to reduce or quit smoking (control). Participants in both arms of the trial were also signposted to usual local support for smoking reduction and quitting. The primary outcome measure is 6-month carbon monoxide-confirmed floating prolonged abstinence following participant self-reported quitting on a mailed questionnaire at 3 and 9 months post-baseline. Participants confirmed as abstinent at 9 months will be followed up at 15 months.

ETHICS AND DISSEMINATION

Approved by SW Bristol National Health Service Research Committee (17/SW/0223). Dissemination will include publication of findings for the stated outcomes, parallel process evaluation and economic evaluation in peer-reviewed journals. Results will be disseminated to trial participants and healthcare providers.

TRIAL REGISTRATION NUMBER

ISRCTN47776579; Pre-results.

Oedema on STIR modified the effect of amoxicillin as treatment for chronic low back pain with Modic changes-subgroup analysis of a randomized trial

Objective

To evaluate potential MRI-defined effect modifiers of amoxicillin treatment in patients with chronic low back pain and type 1 or 2 Modic changes (MCs) at the level of a previous lumbar disc herniation (index level).

Methods

In a prospective trial (AIM), 180 patients (25–64 years; mean age 45; 105 women) were randomised to receive amoxicillin or placebo for 3 months. Primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (0–24 scale) at 1 year. Mean RMDQ score difference between the groups at 1 year defined the treatment effect; 4 RMDQ points defined the minimal clinically important effect. Predefined baseline MRI features of MCs at the index level(s) were investigated as potential effect modifiers. The predefined primary hypothesis was a better effect of amoxicillin when short tau inversion recovery (STIR) shows more MC-related high signal. To evaluate this hypothesis, we pre-constructed a composite variable with three categories (STIR1/2/3). STIR3 implied MC-related STIR signal increases with volume ≥ 25% and height > 50% of vertebral body and maximum intensity increase ≥ 25% and presence on both sides of the disc. As pre-planned, interaction with treatment was analysed using ANCOVA in the per protocol population (n = 155).

Results

The STIR3 composite group (n = 41) and STIR signal volume ≥ 25% alone (n = 45) modified the treatment effect of amoxicillin. As hypothesised, STIR3 patients reported the largest effect (− 5.1 RMDQ points; 95% CI − 8.2 to − 1.9; p for interaction = 0.008).

Conclusions

Predefined subgroups with abundant MC-related index-level oedema on STIR modified the effect of amoxicillin. This finding needs replication and further support.

Key Points

• In the primary analysis of the AIM trial, the effect of amoxicillin in patients with chronic low back pain and type 1 or 2 MCs did not reach the predefined cut-off for clinical importance.

• In the present MRI subgroup analysis of AIM, predefined subgroups with abundant MC-related oedema on STIR reported an effect of amoxicillin.

• This finding requires replication and further support.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07542-w.

Changes in Experimental Pain Sensitivity from Using Home-Based Remotely Supervised Transcranial Direct Current Stimulation in Older Adults with Knee Osteoarthritis

OBJECTIVE

The present study examined the effects of home-based remotely supervised transcranial direct current stimulation on quantitative sensory testing measurements in older adults with knee osteoarthritis. Participants were hypothesized to experience improved pain measurements over time.

DESIGN

Open-label, single-arm trial.

SETTING

Southeast Texas between March and November 2018 at a nursing school and participant homes.

SUBJECTS

Older adults (aged 50-85 years) with self-reported unilateral or bilateral knee osteoarthritis pain who met eligibility criteria set by the American College of Rheumatology.

METHODS

The intervention was applied with a constant current intensity for 20 minutes every weekday for two weeks (10 total sessions). Quantitative measures of pain were collected three times over 10 days (days 1, 5, and 10) and included heat threshold and tolerance, pressure pain threshold, punctate mechanical pain, pain, and conditioned pain modulation. Analyses used nonparametric tests to evaluate differences between day 1 and day 10. Generalized linear mixed models were then used to evaluate change across all three time points for each measure. Bayesian inference was used to provide the posterior probability of longitudinal effects.

RESULTS

Nonparametric tests found improvements in seven measures, and longitudinal models supported improvements in 10 measures, with some nonlinear effects.

CONCLUSIONS

The home-based, remotely supervised intervention improved quantitative measurements of pain in older adults with knee osteoarthritis. This study contributes to the growing body of literature supporting home-based noninvasive stimulation interventions.

Impact of clinical versus radiographic progression on clinical outcomes in metastatic castration-resistant prostate cancer

OBJECTIVES

Unequivocal clinical progression (UCP)-a worsening of clinical status with or without radiographic progression (RAD)-represents a distinct mode of disease progression in metastatic prostate cancer. We evaluated the prevalence, risk factors and the impact of UCP on survival outcomes.

METHODS

A post-hoc analysis of the COU-AA-302, a randomised phase 3 study of abiraterone plus prednisone (AAP) versus prednisone was performed. Baseline characteristics were summarised. Cox proportional-hazards model and Kaplan-Meier method were used for survival and time to event analyses, respectively. Iterative multiple imputation method was used for correlation between clinicoradiographic progression-free survival (crPFS) and overall survival (OS).

RESULTS

Of 736 patients with disease progression, 280 (38%) had UCP-only and 124 (17%) had UCP plus RAD. Prognostic index model high-risk group was associated with increased likelihood of UCP (p<0.0001). Median OS was 25.7 months in UCP-only and 33.0 months for RAD-only (HR 1.39; 95% CI 1.16 to 1.66; p=0.0003). UCP adversely impacted OS in both treatment groups. Lowest OS was seen in patients with prostate specific antigen (PSA)-non-response plus UCP-only progression (median OS 22.6 months (95% CI 20.7 to 24.4)). Including UCP events lowered estimates of treatment benefit-median crPFS was 13.3 months (95% CI 11.1 to 13.8) versus median rPFS of 16.5 months (95% CI 13.8 to 16.8) in AAP group. Finally, crPFS showed high correlation with OS (r=0.67; 95% CI 0.63 to 0.71).

CONCLUSIONS

UCP is a common and clinically relevant phenomenon in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with AAP or prednisone. UCP is prognostic and associated with inferior OS and post-progression survival. A combination of PSA-non-response and UCP identifies patients with poorest survival. When included in PFS analysis, UCP diminishes estimates of treatment benefit. Continued study of UCP in mCRPC is warranted.

Objective analysis of language use in cognitive-behavioral therapy: associations with symptom change in adults with co-occurring substance use disorders and posttraumatic stress

Substance use disorders (SUD) commonly co-occur with posttraumatic stress disorder (PTSD) symptoms, and the comorbidity is prevalent and difficult-to-treat. Few studies have objectively analyzed language use in psychotherapy as a predictor of treatment outcomes. We conducted a secondary analysis of patient language use during cognitive-behavioral therapy (CBT) in a randomized clinical trial, comparing a novel, integrated CBT for PTSD/SUD with standard CBT for SUD. Participants included 37 treatment-seeking, predominantly African-American adults with SUD and at least four symptoms of PTSD. We analyzed transcripts of a single, matched session across both treatment conditions, using the Linguistic Inquiry and Word Count (LIWC) program. The program measures language use across multiple categories. Compared to standard CBT for SUD, patients in the novel, integrated CBT for PTSD/SUD used more negative emotion words, partially consistent with our hypothesis, but less positive emotion words. Further, exploratory analyses indicated an association between usage of cognitive processing words and clinician-observed reduction in PTSD symptoms, regardless of treatment condition. Our results suggest that language use during therapy may provide a window into mechanisms active in therapy.

Evaluating prophylactic heparin in ambulatory patients with solid tumours: a systematic review and individual participant data meta-analysis

BACKGROUND

Study-level meta-analyses provide high-certainty evidence that heparin reduces the risk of symptomatic venous thromboembolism for patients with cancer; however, whether the benefits and harms associated with heparin differ by cancer type is unclear. This individual participant data meta-analysis of randomised controlled trials examines the effect of heparin on survival, venous thromboembolism, and bleeding in patients with cancer in general and by type.

METHODS

In this systematic review and meta-analysis we searched MEDLINE, Embase, and The Cochrane Library for randomised controlled trials comparing parenteral anticoagulants with placebo or standard care in ambulatory patients with solid tumours and no indication for anticoagulation published from the inception of each database to January 14, 2017, and updated it on May 14, 2020, without language restrictions. We calculated the effect of parenteral anticoagulant administration on all-cause mortality, venous thromboembolism occurrence, and bleeding related outcomes through multivariable hierarchical models with patient-level variables as fixed effects and a categorical trial variable as a random effect, adjusting for age, cancer type, and metastatic status. Interaction terms were tested to investigate effects in predefined subgroups. This study is registered with PROSPERO, CRD42013003526.

FINDINGS

We obtained individual participant data from 14 of 20 eligible randomised controlled trials (8278 [79%] of 10 431 participants; 4139 included in the low-molecular-weight heparin group and 4139 in the control group). Meta-analysis showed an adjusted relative risk (RR) of mortality at 1 year of 0·99 (95% CI 0·93-1·06) and a hazard ratio of 1·01 (95% CI 0·96-1·07). The number of patients with venous thromboembolic events was 158 (4·0%) of 3958 with available data in the low-molecular-weight heparin group compared with 279 (7·1%) of 3957 in the control group. Major bleeding events occurred in 71 (1·7%) of 4139 patients in the control population and 88 (2·1%) in the low-molecular-weight heparin group, and minor bleeding events in 478 (12·1%) of 3945 patients with available data in the control group and 652 (16·6%) of 3937 patients in the low-molecular-weight heparin group. The adjusted RR was 0·58 (95% CI 0·47-0·71) for venous thromboembolism, 1·27 (0·92-1·74) for major bleeding, and 1·34 (1·19-1·51) for minor bleeding. Prespecified subgroup analysis of venous thromboembolism occurrence by cancer type identified the most certain benefit from heparin treatment in patients with lung cancer (RR 0·59 [95% CI 0·42-0·81]), which dominated the overall reduction in venous thromboembolism. Certainty of the evidence for the outcomes ranged from moderate to high.

INTERPRETATION

Low-molecular-weight heparin reduces risk of venous thromboembolism without increasing risk of major bleeding compared with placebo or standard care in patients with solid tumours, but it does not improve survival.

FUNDING

Canadian Institutes of Health Research.