Missing Data in Alcohol Clinical Trials with Binary Outcomes

Reductions in World Health Organization Risk Drinking Level Are Associated With Reductions in Alcohol Use Disorder Diagnosis and Criteria: Evidence From an Alcohol Pharmacotherapy Trial

OBJECTIVES

This study aimed to evaluate the validity of World Health Organization (WHO) risk drinking level reductions as meaningful endpoints for clinical practice and research. This study examined whether such reductions were associated with a lower likelihood of a current alcohol use disorder (AUD) diagnosis and fewer AUD criteria.

METHODS

We conducted a secondary data analysis to address these objectives using data from a multisite randomized controlled trial of gabapentin enacarbil extended release in treating moderate to severe AUD among adults (N = 346). Participants received gabapentin enacarbil extended release or placebo for 6 months. The timeline follow-back was used to assess WHO risk drinking level reductions, and the Mini-International Neuropsychiatric Interview was used to assess Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) AUD diagnosis and criteria at baseline (past year) and end of treatment (past month).

RESULTS

Most participants (80.1%) achieved at least a 1-level reduction in the WHO risk drinking levels from baseline to end of treatment, and nearly half of participants (49.8%) achieved at least a 2-level reduction. At least a 1-level reduction or at least a 2-level reduction in WHO risk drinking level predicted lower odds of an active AUD diagnosis (1-level: odds ratio, 0.74 [95% confidence interval (CI), 0.66-0.84]; 2-level: odds ratio, 0.71 [95% CI, 0.64-0.79]) and fewer AUD criteria (1-level: B , -1.66 [95% CI, -2.35 to -0.98]; 2-level: B , -1.76 [95% CI, -2.31 to -1.21]) at end of treatment.

CONCLUSIONS

World Health Organization risk drinking level reductions correlate with Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) AUD diagnosis and criteria, providing further evidence for their use as endpoints in alcohol intervention trials, which has potential implications for broadening the base of AUD treatment.

Response to Letter to the Editors regarding 'A Meta-Regression of Trial Features Predicting the Effects of Alcohol Use Disorder Pharmacotherapies on Drinking Outcomes in Randomized Clinical Trials: A Secondary Data Analysis'

Short Summary: The Letter to the Editors regarding our article was reviewed. The take-home message is that substantively, the authors of the letter are referencing a paper that asks a different research question in a different set of studies. When we ask different questions, we are not surprised when we reach different answers.

Community-based family peer navigator programme to facilitate linkage to coordinated specialty care for early psychosis among Black families in the USA: A protocol for a hybrid type I feasibility study

BACKGROUND

Approximately 70% of Black/African American family members report no contact with mental health providers prior to initial diagnosis and the receipt of services for early psychosis. Black families often encounter barriers and experience delays on the pathway to coordinated specialty care programmes for early psychosis.

METHODS AND ANALYSIS

This mixed-methods study will (1) develop and refine a family peer navigator (FPN) for Black families designed to increase access and engagement in coordinated specialty care and (2) pilot-test FPN for Black families with 40 family members with loved ones at risk for psychosis in a randomised trial to assess the acceptability and feasibility. Families will be randomised to FPN (n=20) or a low-intensive care coordination (n=20). Other outcomes include proposed treatment targets (eg, knowledge, social connectedness), preliminary impact outcomes (time to coordinated specialty care programmes, initial family engagement), and implementation outcomes (acceptability, feasibility, appropriateness).

ETHICS AND DISSEMINATION

Ethics approval has been obtained from Washington State University Institutional Review Board and informed consent will be obtained from all participants. This study will establish an innovative culturally responsive FPN programme and implementation strategy, and generate preliminary data to support a larger hybrid effectiveness-implementation trial. Study findings will be presented at conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05284721.

Treatment retention and reductions in blood alcohol concentration (BAC) during the first 90 days of a telehealth program for alcohol use disorder

Background: Alcohol use disorder (AUD) treatments, including medications, are increasingly offered via telehealth.Objective: This study characterizes 90-day treatment retention and changes in objectively measured blood alcohol concentration (BAC) in a large cohort receiving AUD telehealth.Methods: Patients received AUD treatment through Ria, a virtual (telehealth) program offering AUD treatment that is tailored to patient goals (e.g. abstinence or controlled drinking). Patients were encouraged to complete breathalyzer readings twice daily for measurement-based care. We characterized rates of 90-day treatment retention (i.e. completing a BAC reading or medical/coaching encounter on the 90^th day or later) and used growth curve analyses to model changes in daily estimated peak BAC over 90 days.Results: Of 4121 patients (51.5% women), 50.1% had 90-day treatment retention (n = 2066, 52.2% women). Most patients received prescriptions for AUD medications (84.6%) and completed encounters with medical providers (86.7%) and coaches (86.1%). Patients with 90-day retention provided 184,817 BAC readings in the first 90 days. Growth curve analyses revealed significant reductions in daily estimated peak BAC (p < .001) from a mean of 0.092 (day 1) to 0.038 (day 90). Similar magnitudes of BAC reduction were observed for men and women and for patients with abstinence and controlled drinking goals.Conclusion: Telehealth appears to be a viable approach to delivering AUD treatments in a manner that promotes drinking reductions. Telehealth approaches can yield reductions in objectively measured BAC, including for some patient subgroups that have historically faced greater stigma in AUD treatment settings, such as women and people with non-abstinence drinking goals.

A Meta-Regression of Trial Features Predicting the Effects of Alcohol Use Disorder Pharmacotherapies on Drinking Outcomes in Randomized Clinical Trials: A Secondary Data Analysis

AIMS

To test whether two critical design features, inclusion criteria of required pre-trial abstinence and pre-trial alcohol use disorder (AUD) diagnosis, predict the likelihood of detecting treatment effects in AUD pharmacotherapy trials.

METHODS

This secondary data analysis used data collected from a literature review to identify randomized controlled pharmacotherapy trials for AUD. Treatment outcomes were selected into abstinence and no heavy drinking. Target effect sizes were calculated for each outcome and a meta-regression was conducted to test the effects of required pre-trial abstinence, required pre-trial AUD diagnosis, and their interaction on effect sizes. A sub-analysis was conducted on trials, which included FDA-approved medications for AUD.

RESULTS

In total, 118 studies testing 19 medications representing 21,032 treated participants were included in the meta-regression analysis. There was no significant effect of either predictor on abstinence or no heavy drinking outcomes in the full analysis or in the sub-study of FDA-approved medications.

CONCLUSION

By examining these design features in a quantitative, rather than qualitative, fashion the present study advances the literature and shows that requiring AUD diagnosis or requiring pre-trial abstinence do not impact the likelihood of a significant medication effect in the trial.

Reward-related attentional capture predicts non-abstinence during a one-month abstinence challenge

BACKGROUND

While it is generally recognised that cognitive attributes can predict behaviour change outcomes in the field of addiction this question is typically studied in treatment seeking samples (to predict treatment outcomes and relapse). However the concept of behaviour change applies to the entire spectrum of addiction-like behaviours and initiatives such as temporary abstinence challenges offer insight into an understudied but equally relevant point of the spectrum. Thus the current study examined whether reward-related attentional capture predicted non-abstinence during IkPas (the Dutch national dry January campaign translated: NoThanks!).

METHOD

Participants included 1130 adults who had complete baseline data and performed above chance level on the cognitive task. Of these 683 participants completed the post-IkPas assessment and were included in the primary analysis. A binary logistic regression examined whether reward-related attentional capture predicted drinking during IkPas controlling for alcohol use at baseline (among other potential confounders).

RESULTS

Participants who showed greater reward-related attentional capture before IkPas were more likely to not remain abstinent from drinking during IkPas (p = .014). Findings were replicated using multiple imputation to replace missing data (p = .013).

CONCLUSION

These findings provide important insights into the cognitive mechanisms that support successful behaviour change such as the ability to ignore task-irrelevant reward cues and may inform the development of tools that individuals could use to maximise their likelihood of achieving successful behaviour change.

Validity and measurement invariance of the Addictions Neuroclinical Assessment incentive salience domain among treatment-seekers with alcohol use disorder

Incentive salience, or the attribution of motivational value to stimuli, is a biopsychological process that is disrupted in alcohol use disorder (AUD). The Addictions Neuroclinical Assessment (ANA) is a framework to characterize heterogeneity in addiction and establish a common assessment battery for research and clinical use. The ANA framework hypothesizes three constructs that correspond to processes in the etiology, course, and treatment of addiction: incentive salience, negative emotionality, and executive function. The current study extends prior findings on the ANA by validating the incentive salience construct among participants (n = 563) in a multisite prospective study of individuals entering treatment for AUD. We used confirmatory factor analysis to test a one-factor model of incentive salience. Indicators included items assessing perception of urges to drink from the Alcohol Dependence Scale, Impaired Control Scale, and Marlatt Relapse Interview. Results indicated the one-factor model fit the data well (χ² (12) = 19.42, p = .08; RMSEA = 0.034 [90% CI: 0.000, 0.060], CFI = 0.992) and was measurement invariant across sex. Incentive salience was associated with drinking patterns (e.g., drinks per day, r = 0.447 [95% CI: 0.379, 0.514]); reasons for drinking (urges/temptation r = 0.529 [95% CI: 0.460, 0.599]); testing personal control, r = 0.384 (95% CI: 0.308, 0.461); social pressure, r = 0.549 (95% CI: 0.481, 0.617); and family history of AUD, r = 0.134. The incentive salience factor demonstrated greater predictive validity for drinking outcomes compared to alternative preexisting scales. Overall, this study provides support for the construct validity and measurement invariance of the ANA incentive salience construct in a sample of individuals seeking AUD treatment.

World Health Organization risk drinking level reductions are associated with improved functioning and are sustained among patients with mild, moderate and severe alcohol dependence in clinical trials in the United States and United Kingdom

AIMS

To examine whether World Health Organization (WHO) risk-level reductions in drinking were achievable, associated with improved functioning and maintained over time among patients at varying initial alcohol dependence severity levels. Design and setting Secondary data analysis of multi-site randomized clinical trials: the US Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence (COMBINE) study and the UK Alcohol Treatment Trial (UKATT).

PARTICIPANTS

Individuals with alcohol dependence enrolled in COMBINE (n = 1383; 68.8% male) and seeking treatment for alcohol problems in UKATT (n = 742; 74.1% male). Interventions Naltrexone, acamprosate or placebo, and combined behavioral intervention or medication management in COMBINE. Social behavior network therapy or motivational enhancement therapy in UKATT.

MEASUREMENTS

WHO risk-level reductions were assessed via the calendar method. Alcohol dependence was measured by the Alcohol Dependence Scale, the Leeds Dependence Questionnaire and the Diagnostic and Statistical Manual of Mental Disorders. Measures of functioning included alcohol-related consequences (Drinker Inventory of Consequences and Alcohol Problems Questionnaire), mental health (Short Form Health Survey) and liver enzyme tests.

FINDINGS

One- and two-level reductions in WHO risk levels in the last month of treatment were maintained at the 1-year follow-up [adjusted odds ratio (OR), 95% confidence interval (CI) = one-level reduction in COMBINE: 3.51 (2.73, 4.29) and UKATT: 2.65 (2.32, 2.98)] and associated with fewer alcohol-related consequences [e.g. B, 95% CI = one-level reduction COMBINE: -26.22 (-30.62, -21.82)], better mental health [e.g. B, 95% CI = one-level reduction UKATT: 9.53 (7.36, 11.73)] and improvements in γ-glutamyltransferase [e.g. B, 95% CI = one-level reduction UKATT: -89.77 (-122.50, -57.04)] at the end of treatment, even among patients with severe alcohol dependence. Results were similar when abstainers were excluded. Conclusions Reductions in World Health Organization risk levels for alcohol consumption appear to be achievable, associated with better functioning and maintained over time in both the United States and the United Kingdom.

Potential impact of missing outcome data on treatment effects in systematic reviews: imputation study

OBJECTIVE

To assess the risk of bias associated with missing outcome data in systematic reviews.

DESIGN

Imputation study.

SETTING

Systematic reviews.

POPULATION

100 systematic reviews that included a group level meta-analysis with a statistically significant effect on a patient important dichotomous efficacy outcome.

MAIN OUTCOME MEASURES

Median percentage change in the relative effect estimate when applying each of the following assumption (four commonly discussed but implausible assumptions (best case scenario, none had the event, all had the event, and worst case scenario) and four plausible assumptions for missing data based on the informative missingness odds ratio (IMOR) approach (IMOR 1.5 (least stringent), IMOR 2, IMOR 3, IMOR 5 (most stringent)); percentage of meta-analyses that crossed the threshold of the null effect for each method; and percentage of meta-analyses that qualitatively changed direction of effect for each method. Sensitivity analyses based on the eight different methods of handling missing data were conducted.

RESULTS

100 systematic reviews with 653 randomised controlled trials were included. When applying the implausible but commonly discussed assumptions, the median change in the relative effect estimate varied from 0% to 30.4%. The percentage of meta-analyses crossing the threshold of the null effect varied from 1% (best case scenario) to 60% (worst case scenario), and 26% changed direction with the worst case scenario. When applying the plausible assumptions, the median percentage change in relative effect estimate varied from 1.4% to 7.0%. The percentage of meta-analyses crossing the threshold of the null effect varied from 6% (IMOR 1.5) to 22% (IMOR 5) of meta-analyses, and 2% changed direction with the most stringent (IMOR 5).

CONCLUSION

Even when applying plausible assumptions to the outcomes of participants with definite missing data, the average change in pooled relative effect estimate is substantive, and almost a quarter (22%) of meta-analyses crossed the threshold of the null effect. Systematic review authors should present the potential impact of missing outcome data on their effect estimates and use this to inform their overall GRADE (grading of recommendations assessment, development, and evaluation) ratings of risk of bias and their interpretation of the results.

A randomized comparison of extended-release naltrexone with or without patient navigation vs enhanced treatment-as-usual for incarcerated adults with opioid use disorder

The high prevalence of opioid use among justice-involved adults make jails an exceptional setting to initiate opioid use disorder (OUD) treatment, but optimal strategies for delivering these interventions are still not well understood. The objective of this study was to conduct a randomized controlled trial to assess the effectiveness of extended-release naltrexone (XR-NTX, Vivitrol®; Alkermes Inc) alone or in conjunction with patient navigation (XR-NTX + PN) for jail inmates with OUD. We randomized a sample of 135 sentenced jail inmates with moderate to severe OUD to (1) XR-NTX only; (2) XR-NTX + PN; or (3) enhanced treatment-as-usual (ETAU) with drug education, each initiated prior to release from jail. We scheduled follow-up data assessments at 1, 3, 6, and 12 months post-release. Primary outcomes were opioid use (based on Timeline Followback Interview and Addiction Severity Index) and meeting CIDI DSM-5 criteria for OUD 6 months postrelease. We also measured treatment adherence, HIV risk, and recidivism. XR-NTX participants received a mean of 2.26 of 7 possible injections compared to XR-NTX + PN participants, who received a mean of 2.93 injections (Cohen's d = 0.33, 95% CI: -0.09 to 0.74). Thirty-six percent of patients in XR-NTX + PN attended at least one postrelease PN session. We found no significant differences by study condition six months after release from jail for the primary outcomes of any opioid use (ETAU: 17%, XR-NTX: 16%, XR-NTX + PN: 29%) and past 30-day OUD (ETAU: 8%, XR-NTX: 11%, XR-NTX + PN: 10%). Secondary outcomes of rearrest and HIV risk also were similar across groups, with the exception of lower sex-related HIV risk among those in the XR-NTX condition at 12 months. This study did not show superior outcomes of XR-NTX or XR-NTX + PN with regard to opioid use or recidivism outcomes, relative to ETAU. It did, however, highlight the difficulties with adherence to XR-NTX and PN interventions in OUD patients initiating treatment in jail.

Predictive value of non-consumption outcome measures in alcohol use disorder treatment

BACKGROUND AND AIMS

For decades, researchers have called for the systematic inclusion of non-consumption outcomes, such as alcohol-related consequences and temptation/craving, in addition to consumption outcomes (e.g. percentage of days abstinent) to evaluate alcohol use disorder (AUD) treatment efficacy. However, Food and Drug Administration (FDA) guidelines for alcohol medications development suggest that non-consumption outcomes may be insensitive to changes that occur within AUD treatment trial assessment windows, although this has never been directly tested. We aimed to measure the predictive value of diagnostically related, non-consumption measures of AUD treatment effects.

METHODS

Pre- to post-treatment effect sizes were examined. Logistic regression analyses were used to test the predictive value of non-consumption outcome measures that were administered in the COMBINE (Combined Pharmacotherapies and Behavioral Interventions for Alcohol Dependence) Study and Project MATCH (Matching Alcoholism Treatment to Client Heterogeneity) in detecting 12-month outcomes following treatment.

RESULTS

Pre- to post-treatment effect sizes suggested that non-consumption measures changed during the course of treatment; effect sizes for temptation/craving, self-efficacy, consequences and consumption variables were mostly medium to large (medium effect sizes were 0.2 < dz < 0.8, large effect sizes were dz > 0.8). The regression results indicated temptation/craving and self-efficacy predicted 12-month drinking outcomes in COMBINE and MATCH, and drinking consequences predicted 12-month drinking outcomes in COMBINE.

CONCLUSIONS

Self-report measures of temptation and alcohol craving can change as a result of alcohol dependence treatment and can predict drinking outcomes.

Maintenance of World Health Organization Risk Drinking Level Reductions and Posttreatment Functioning Following a Large Alcohol Use Disorder Clinical Trial

Background

Reductions in the World Health Organization (WHO) risk drinking levels have been proposed as an alternative primary outcome for alcohol clinical trials. Yet, little is known about whether reductions in WHO risk drinking levels can be maintained over time. The current study examined whether reductions in WHO risk drinking levels were maintained for up to 1 year following treatment, and whether reductions over time were associated with improvements in functioning.

Methods

Secondary data analysis of individuals with alcohol dependence (n = 1,226) enrolled in the COMBINE study, a multisite, randomized, placebo‐controlled clinical trial. Logistic regression was used to examine the maintenance of end‐of‐treatment WHO risk level reductions and WHO risk level reductions at the 1‐year follow‐up. Repeated‐measures mixed models were used to examine the association between WHO risk level reductions and functional outcomes over time.

Results

Achieving at least a 1‐ or 2‐level reduction in risk by the end of treatment was significantly associated with WHO risk level reductions at the 1‐year follow‐up assessment (p < 0.001). Among individuals who achieved at least a 1‐level reduction by the end of treatment, 85.5% reported at least a 1‐level reduction at the 1‐year follow‐up. Among individuals who achieved at least a 2‐level reduction by the end of treatment, 77.8% reported at least a 2‐level reduction at the 1‐year follow‐up. WHO risk level reductions were associated with significantly lower alcohol consumption, better physical health (p < 0.01), and fewer alcohol‐related consequences (p < 0.001) up to 1 year following treatment.

Conclusions

One‐ and 2‐level reductions in WHO risk levels during alcohol treatment were maintained after treatment and associated with better functioning over time. These findings support the use of the WHO risk level reductions as an outcome measure that reflects clinically significant improvement in how individuals seeking treatment for alcohol use disorder feel and function.

Evaluation of Drinking Risk Levels as Outcomes in Alcohol Pharmacotherapy Trials: A Secondary Analysis of 3 Randomized Clinical Trials

IMPORTANCE

The US Food and Drug Administration recognizes total abstinence and no heavy drinking days as outcomes for pivotal pharmacotherapy trials for alcohol use disorder (AUD). Many patients have difficulty achieving these outcomes, which can discourage seeking treatment and has slowed the development of medications that affect alcohol use.

OBJECTIVE

To compare 2 drinking-reduction outcomes with total abstinence and no heavy drinking outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Data were obtained from 3 multisite, randomized, placebo-controlled clinical trials of medications for treating alcohol dependence (naltrexone, varenicline, and topiramate) in adults with DSM-IV-categorized alcohol dependence.

MAIN OUTCOMES AND MEASURES

Within each trial, the percentage of participants in active and placebo conditions who met responder definitions of abstinence, no heavy drinking days, a WHO 1-level reduction, and a WHO 2-level reduction was computed by month with corresponding effect sizes (Cohen h).

RESULTS

Across the 3 trials (N = 1169; mean [SD] age, 45 [10] years; 824 [70.5%] men), the percentage of participants classified as responders during the last 4 weeks of treatment was lowest for abstinence (naltrexone, 34.7% [100 of 288]; varenicline, 7.3% [7 of 96]; topiramate, 11.7% [21 of 179]) followed by no heavy drinking days (naltrexone, 51.0% [147 of 288]; varenicline, 24.0% [23 of 96]; topiramate, 20.7% [37 of 179]), WHO 2-level reduction (naltrexone, 75.0% [216 of 288]; varenicline, 55.2% [53 of 96]; topiramate, 44.7% [80 of 179]), and WHO 1-level reduction (naltrexone, 83.3% [240 of 288]; varenicline, 69.8 [67 of 96]; topiramate, 54.7% [98 of 179]) outcomes. Standardized treatment effects observed for the WHO 2-level reduction outcomes (naltrexone, Cohen h = 0.214 [95% CI, 0.053 -0.375]; varenicline, 0.273 [95% CI, -0.006 to 0.553]; topiramate, 0.230 [95% CI, 0.024-0.435]) and WHO 1-level reduction (naltrexone, Cohen h = 0.116 [95% CI, -0.046 to 0.277]; varenicline, 0.338 [95% CI, 0.058-0.617]; topiramate, 0.014 [95% CI, -0.192 to 0.219]) were comparable with those obtained using abstinence (naltrexone, Cohen h = 0.142 [95% CI, -0.020 to 0.303]; varenicline, 0.146 [95% CI, -0.133 to 0.426]; topiramate, 0.369 [95% CI, 0.163-0.574]) and no heavy drinking days (naltrexone, Cohen h = 0.140 [95% CI, -0.021 to 0.302]; varenicline, 0.232 [95% CI, -0.048 to 0.511]; topiramate, 0.207 [95% CI, 0.002-0.413]).

CONCLUSIONS AND RELEVANCE

WHO drinking risk level reductions appear to be worthwhile indicators of treatment outcome in AUD pharmacotherapy trials. These outcomes may align with drinking reduction goals of many patients and capture clinically meaningful improvements experienced by more patients than either abstinence or no heavy drinking days.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT00006206; NCT01146613; NCT00210925.

Missing Data Techniques and the Statistical Conclusion Validity of Survey-Based Alcohol and Drug Use Research Studies: A Review and Comment on Reproducibility

The goal of the present review was to examine whether or not the use of modern missing data techniques impacts the statistical conclusion validity of research on alcohol and drug use outcomes in survey-based research studies. We identified 28 papers and received complete case data from the authors of 12 studies. Seven studies (25%) reported the missing data pattern (missing not at random [MNAR], missing at random [MAR], missing completely at random [MCAR]), 15 studies (53.6%) indicated the amount of missing observations in the data set, and a significant proportion of studies ( n = 13, 46.4%) did not report any of the conditions or assumptions under which the missing data analysis was performed or implemented. Six of the 12 (50%) studies analyzed reported a different number of statistically significant associations between the complete case and full sample analyses. Efforts should be made to make missing data analysis more accessible, easy to implement and report to improve transparency and reproducibility of findings.

Efficacy, tolerability, and safety of low-dose and high-dose baclofen in the treatment of alcohol dependence: A systematic review and meta-analysis

A systematic review of the current literature on the efficacy of baclofen, particularly the effect of dosing, for the treatment of alcohol dependence (AD) is missing. We therefore conducted a systematic review and meta-analysis of currently available randomized placebo-controlled trials (RCTs). A systematic literature search for RCTs in AD patients comparing baclofen to placebo was performed in September 2017. The effect of baclofen treatment, and the moderating effects of baclofen dosing (low-dose (LDB) 30-60 mg versus high-dose (HDB) targeted as >60 mg/day), and the amount of alcohol consumption before inclusion were studied. Three treatment outcomes were assessed: time to lapse (TTL), percentage days abstinent (PDA), and percentage of patients abstinent at end point (PAE). 13 RCTs from 39 records were included. Baclofen was superior to placebo with significant increases in TTL (8 RCTs, 852 patients; SMD=0.42; 95% CI 0.19-0.64) and PAE (8 RCTs, 1244 patients; OR=1.93; 95% CI 1.17-3.17), and a non-significant increase in PDA (7 RCTs, 457 patients; SMD=0.21; 95% CI -0.24 to 0.66). Overall, studies with LDB showed better efficacy than studies with HDB. Furthermore, tolerability of HDB was low, but serious adverse events were rare. Meta-regression analysis showed that the effects of baclofen were stronger when daily alcohol consumption before inclusion was higher. Baclofen seems to be effective in the treatment of AD, especially among heavy drinkers. HDB is not necessarily more effective than LDB with low tolerability of HDB being an import limitation.

Missing data may lead to changes in hip fracture database studies: a study of the American College of Surgeons National Surgical Quality Improvement Program

AIMS

The aims of this study were to characterize the frequency of missing data in the National Surgical Quality Improvement Program (NSQIP) database and to determine how missing data can influence the results of studies dealing with elderly patients with a fracture of the hip.

PATIENTS AND METHODS

Patients who underwent surgery for a fracture of the hip between 2005 and 2013 were identified from the NSQIP database and the percentage of missing data was noted for demographics, comorbidities and laboratory values. These variables were tested for association with 'any adverse event' using multivariate regressions based on common ways of handling missing data.

RESULTS

A total of 26 066 patients were identified. The rate of missing data was up to 77.9% for many variables. Multivariate regressions comparing three methods of handling missing data found different risk factors for postoperative adverse events. Only seven of 35 identified risk factors (20%) were common to all three analyses.

CONCLUSION

Missing data is an important issue in national database studies that researchers must consider when evaluating such investigations. Cite this article: Bone Joint J 2018;100-B:226-32.

Results of Database Studies in Spine Surgery Can Be Influenced by Missing Data

BACKGROUND

National databases are increasingly being used for research in spine surgery; however, one limitation of such databases that has received sparse mention is the frequency of missing data. Studies using these databases often do not emphasize the percentage of missing data for each variable used and do not specify how patients with missing data are incorporated into analyses. This study uses the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to examine whether different treatments of missing data can influence the results of spine studies.

QUESTIONS/PURPOSES

(1) What is the frequency of missing data fields for demographics, medical comorbidities, preoperative laboratory values, operating room times, and length of stay recorded in ACS-NSQIP? (2) Using three common approaches to handling missing data, how frequently do those approaches agree in terms of finding particular variables to be associated with adverse events? (3) Do different approaches to handling missing data influence the outcomes and effect sizes of an analysis testing for an association with these variables with occurrence of adverse events?

METHODS

Patients who underwent spine surgery between 2005 and 2013 were identified from the ACS-NSQIP database. A total of 88,471 patients undergoing spine surgery were identified. The most common procedures were anterior cervical discectomy and fusion, lumbar decompression, and lumbar fusion. Demographics, comorbidities, and perioperative laboratory values were tabulated for each patient, and the percent of missing data was noted for each variable. These variables were tested for an association with "any adverse event" using three separate multivariate regressions that used the most common treatments for missing data. In the first regression, patients with any missing data were excluded. In the second regression, missing data were treated as a negative or "reference" value; for continuous variables, the mean of each variable's reference range was computed and imputed. In the third regression, any variables with > 10% rate of missing data were removed from the regression; among variables with ≤ 10% missing data, individual cases with missing values were excluded. The results of these regressions were compared to determine how the different treatments of missing data could affect the results of spine studies using the ACS-NSQIP database.

RESULTS

Of the 88,471 patients, as many as 4441 (5%) had missing elements among demographic data, 69,184 (72%) among comorbidities, 70,892 (80%) among preoperative laboratory values, and 56,551 (64%) among operating room times. Considering the three different treatments of missing data, we found different risk factors for adverse events. Of 44 risk factors found to be associated with adverse events in any analysis, only 15 (34%) of these risk factors were common among the three regressions. The second treatment of missing data (assuming "normal" value) found the most risk factors (40) to be associated with any adverse event, whereas the first treatment (deleting patients with missing data) found the fewest associations at 20. Among the risk factors associated with any adverse event, the 10 with the greatest effect size (odds ratio) by each regression were ranked. Of the 15 variables in the top 10 for any regression, six of these were common among all three lists.

CONCLUSIONS

Differing treatments of missing data can influence the results of spine studies using the ACS-NSQIP. The current study highlights the importance of considering how such missing data are handled.

CLINICAL RELEVANCE

Until there are better guidelines on the best approaches to handle missing data, investigators should report how missing data were handled to increase the quality and transparency of orthopaedic database research. Readers of large database studies should note whether handling of missing data was addressed and consider potential bias with high rates or unspecified or weak methods for handling missing data.

Tdap Vaccination Among Healthcare Personnel, Internet Panel Survey, 2012-2014

INTRODUCTION

Healthcare personnel (HCP) are at risk for pertussis infection exposure or transmitting the disease to patients in their work settings. The Advisory Committee on Immunization Practices recommends tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination for HCP to minimize these risks. This study assessed Tdap vaccination coverage among U.S. HCP by sociodemographic and occupation-related characteristics.

METHODS

The 2012, 2013, and 2014 Internet Panel Surveys were analyzed in 2015 to assess HCP Tdap vaccination. Effective sample sizes for 2012, 2013, and 2014 survey years were 2,038, 1613, and 1633, respectively. Missing values were assigned using multiple imputation. Multivariable logistic regression identified factors independently associated with HCP Tdap vaccination. Statistical measures were calculated with an assumption of random sampling.

RESULTS

Overall, Tdap vaccination coverage among HCP was 34.8% (95% CI=30.6%, 39.0%); 40.2% (95% CI=36.1%, 44.4%); and 42.4% (95% CI=38.7%, 46.0%) in 2012, 2013, and 2014, respectively. Nurse practitioners/physician's assistants, physicians, nurses, and HCP working in hospitals and ambulatory care settings had higher Tdap coverage. Having contact with an infant aged ≤6 months and influenza vaccination receipt were associated with increased Tdap vaccination. Non-Hispanic black race/ethnicity, having an associate/bachelor's degree, being below poverty, non-clinical personnel status, and working in a long-term care setting were associated with decreased Tdap vaccination.

CONCLUSIONS

HCP Tdap vaccination coverage increased during 2012-2014; however, coverage remains low. Vaccination coverage varied widely by healthcare occupation, occupational setting, and sociodemographic characteristics. Evidence-based employer strategies used to increase HCP influenza vaccination, if applied to Tdap, may increase Tdap coverage.

Volatility and change in chronic pain severity predict outcomes of treatment for prescription opioid addiction

BACKGROUND AND AIMS

Buprenorphine-naloxone (BUP-NLX) can be used to manage prescription opioid addiction among persons with chronic pain, but post-treatment relapse is common and difficult to predict. This study estimated whether changes in pain over time and pain volatility during BUP-NLX maintenance would predict opioid use during the taper BUP-NLX taper.

DESIGN

Secondary analysis of a multi-site clinical trial for prescription opioid addiction, using data obtained during a 12-week BUP-NLX stabilization and 4-week BUP-NLX taper.

SETTING

Community clinics affiliated with a national clinical trials network in 10 US cities.

PARTICIPANTS

Subjects with chronic pain who entered the BUP-NLX taper phase (n = 125) with enrollment occurring from June 2006 to July 2009 (52% male, 88% Caucasian, 31% married).

MEASUREMENTS

Outcomes were weekly biologically verified and self-reported opioid use from the 4-week taper phase. Predictors were estimates of baseline severity, rate of change and volatility in pain from weekly self-reports during the 12-week maintenance phase.

FINDINGS

Controlling for baseline pain and treatment condition, increased pain [odds ratio (OR) = 2.38, P = 0.02] and greater pain volatility (OR = 2.43, P = 0.04) predicted greater odds of positive opioid urine screen during BUP-NLX taper. Increased pain (IRR = 1.40, P = 0.04) and greater pain volatility [incidence-rate ratio (IRR) = 1.66, P = 0.009] also predicted greater frequency of self-reported opioid use.

CONCLUSIONS

Adults with chronic pain receiving out-patient treatment with buprenorphine-naloxone (BUP-NLX) for prescription opioid addiction have an elevated risk for opioid use when tapering off maintenance treatment. Those with relative persistence in pain over time and greater volatility in pain during treatment are less likely to sustain abstinence during BUP-NLX taper.

Predictors and Outcomes of Twelve-Step Sponsorship of Stimulant Users: Secondary Analyses of a Multisite Randomized Clinical Trial

OBJECTIVE

This secondary data analysis explored predictors and outcomes of having a 12-step sponsor among individuals receiving treatment for stimulant use disorders, inclusive of four types of 12-step groups (Narcotics Anonymous, Alcoholics Anonymous, Cocaine Anonymous, and Crystal Meth Anonymous).

METHOD

For a multisite randomized clinical trial, participants (N = 471; 59% women) were recruited among adult patients in 10 U.S. community treatment programs. Participants were randomized into treatment as usual (TAU) or a 12-step facilitation (TSF) intervention: Stimulant Abuser Groups to Engage in 12-Step (STAGE-12). Logistic regression analyses explored the extent to which participants obtained sponsors, including the extent to which treatment condition and other predictors (12-step experiences, expectations, and beliefs) were associated with having a sponsor. The relationship between end-of-treatment sponsorship and follow-up substance use outcomes was also tested.

RESULTS

Participants were more likely to have a sponsor at the end of treatment and 3-month follow-up, with the STAGE-12 condition having higher sponsorship rates. Twelve-step meeting attendance and literature reading during the treatment period predicted having a sponsor at the end of treatment. Sponsorship at the end of treatment predicted a higher likelihood of abstinence from stimulant use and having no drug-related problems at follow-up.

CONCLUSIONS

This study extends previous research on sponsorship, which has mostly focused on alcohol use disorders, by indicating that sponsorship is associated with positive outcomes for those seeking treatment from stimulant use disorders. It also suggests that sponsorship rates can be improved for those seeking treatment from stimulant use disorders through a short-term TSF intervention.

Prediction of Suicide Ideation and Attempt Among Substance-Using Patients in Primary Care

BACKGROUND

Suicide is a major public health concern, particularly among people who use illicit substances and/or non-prescribed medications.

METHODS

The present study prospectively assessed the incidence and predictors of suicidal ideation (SI) and suicide attempt (SA) among 868 substance-using patients over 12 months after receiving primary care within seven public primary care clinics.

RESULTS

Participants reported a high incidence of SI (25.9%) and SA (7.1%) over the year following primary care visits. Suicidality was elevated in patients who were female; lacked a high school diploma; were unemployed; reported depression, anxiety, hallucinations, concentration difficulty, or violent behavior; used nicotine or stimulants; used the emergency department or mental health services in the past 90 days; reported current quality-of-life impairment in mobility or usual activities; or reported recent SI or lifetime SA at baseline. In multiple regression analyses, only past 30-day SI, any lifetime SA, past 90-day violent behavior, and current impairment due to anxiety or depression at baseline uniquely predicted SI or SA beyond other variables.

CONCLUSIONS

Results support the need for screening for suicidality among primary care patients who use illicit substances and identify key of these patients who are at particularly elevated risk for suicidality.