scholarly journals Design and analysis of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria: Small sample considerations for cluster-randomized trials with count data

2021 ◽  
pp. 174077452110285
Author(s):  
Conner L Jackson ◽  
Kathryn Colborn ◽  
Dexiang Gao ◽  
Sangeeta Rao ◽  
Hannah C Slater ◽  
...  
Keyword(s):  
Randomized Trial ◽  
Cluster Randomized Trial ◽  
Mixed Effects ◽  
Small Sample ◽  
Mixed Effects Models ◽  
Type I ◽  
Cluster Randomized ◽  
Cluster Level ◽  
Generalized Estimating

Background: Cluster-randomized trials allow for the evaluation of a community-level or group-/cluster-level intervention. For studies that require a cluster-randomized trial design to evaluate cluster-level interventions aimed at controlling vector-borne diseases, it may be difficult to assess a large number of clusters while performing the additional work needed to monitor participants, vectors, and environmental factors associated with the disease. One such example of a cluster-randomized trial with few clusters was the “efficacy and risk of harms of repeated ivermectin mass drug administrations for control of malaria” trial. Although previous work has provided recommendations for analyzing trials like repeated ivermectin mass drug administrations for control of malaria, additional evaluation of the multiple approaches for analysis is needed for study designs with count outcomes. Methods: Using a simulation study, we applied three analysis frameworks to three cluster-randomized trial designs (single-year, 2-year parallel, and 2-year crossover) in the context of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria. Mixed-effects models, generalized estimating equations, and cluster-level analyses were evaluated. Additional 2-year parallel designs with different numbers of clusters and different cluster correlations were also explored. Results: Mixed-effects models with a small sample correction and unweighted cluster-level summaries yielded both high power and control of the Type I error rate. Generalized estimating equation approaches that utilized small sample corrections controlled the Type I error rate but did not confer greater power when compared to a mixed model approach with small sample correction. The crossover design generally yielded higher power relative to the parallel equivalent. Differences in power between analysis methods became less pronounced as the number of clusters increased. The strength of within-cluster correlation impacted the relative differences in power. Conclusion: Regardless of study design, cluster-level analyses as well as individual-level analyses like mixed-effects models or generalized estimating equations with small sample size corrections can both provide reliable results in small cluster settings. For 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria, we recommend a mixed-effects model with a pseudo-likelihood approximation method and Kenward–Roger correction. Similarly designed studies with small sample sizes and count outcomes should consider adjustments for small sample sizes when using a mixed-effects model or generalized estimating equation for analysis. Although the 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria is already underway as a parallel trial, applying the simulation parameters to a crossover design yielded improved power, suggesting that crossover designs may be valuable in settings where the number of available clusters is limited. Finally, the sensitivity of the analysis approach to the strength of within-cluster correlation should be carefully considered when selecting the primary analysis for a cluster-randomized trial.

scholarly journals On Small-Sample Inference in Multiphase Stepped Wedge Cluster Randomized Trial (MSW-CRT) With Binary Outcomes

2021 ◽  
Author(s):  
Jing Peng ◽  
Abigail Shoben ◽  
Pengyue Zhang ◽  
Philip M. Westgate ◽  
Soledad Fernandez
Keyword(s):  
Randomized Trial ◽  
Type I Error ◽  
Event Rate ◽  
Cluster Randomized Trial ◽  
Small Sample ◽  
Binary Outcomes ◽  
Type I ◽  
Stepped Wedge ◽  
Number Of Clusters ◽  
Cluster Randomized

Abstract BackgroundThe stepped wedge cluster randomized trial (SW-CRT) design is now preferred for many health- related trials because of its flexibility on resource allocation and clinical ethics concerns. However, as a necessary extension of studying multiple interventions, multiphase stepped wedge designs (MSW-CRT) have not been studied adequately. Since estimated intervention effect from Generalized estimating equations (GEE) has a population-average interpretation, valid inference methods for binary outcomes based on GEE are preferred by public health policy makers.MethodsWe form hypothesis testing of add-on effect of a second treatment based on GEE analysis in an MSW-CRT design with limited number of clusters. Four variance-correction estimators are used to adjust the bias of the sandwich estimator. Simulation studies have been used to compare the statistical power and type I error rate of these methods under different correlation matrices.Results We demonstrate that an average estimator with t(I-3) can stably maintain type I error close to the nominal level with limited sample sizes in our settings. We show that power of testing the add-on effect depends on the baseline event rate, effect sizes of two interventions and the number of clusters. Moreover, by changing the design with including more sequences, power benefit can be achieved. ConclusionsFor designing the MSW-CRT, we suggest using more sequences and checking event rate after initiating the first intervention via interim analysis. When the number of clusters is not very large in MSW-CRTs, inference can be conduct using GEE analysis with an average estimator with t(I-3) sampling distribution.

Abstract P494: Long-term Outcomes of a Cluster-randomized Trial Testing the Effects Blood Pressure Telemonitoring and Pharmacist Management

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Karen L Margolis ◽  
Stephen E Asche ◽  
Anna R Bergdall ◽  
Steven P Dehmer ◽  
Beverly B Green ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Randomized Trial ◽  
Clinical Care ◽  
Cluster Randomized Trial ◽  
Home Blood Pressure ◽  
Uncontrolled Hypertension ◽  
Routine Clinical Care ◽  
Differential Reduction ◽  
Cluster Randomized

Background/Aims: Hypertension is a common condition and leading cause of cardiovascular disease. We previously reported results of a cluster-randomized trial evaluating a home blood pressure (BP) telemonitoring and pharmacist management intervention, with significant reductions in BP favoring the intervention arm over 18 months. This analysis examined the durability of the intervention effect on BP through 54 months of follow-up and compared BP measurements performed in the research clinic and in routine clinical care. Methods: The Hyperlink trial randomized 16 primary care clinics having 450 study-enrolled patients with uncontrolled hypertension to either Telemonitoring Intervention (TI) or usual care (UC) study arms. BP was measured as the mean of 3 measurements obtained at each research clinic visit. General linear mixed models utilizing a direct likelihood-based ignorable approach for missing data were used to examine change from baseline to 54 months in systolic and diastolic BP (SBP and DBP). Results: Research clinic BP measurements were obtained from 326 (72%) study patients at the 54 month follow-up visit. Routine clinical care BP measurements were obtained from 444 (99%) of study patients from 7025 visits during the follow-up period. For TI patients, based on research clinic measurements baseline SBP was 148.2 mm Hg and 54 month follow-up was 131.2 mm Hg (-17.0 mm Hg, p<.001). For UC patients, baseline SBP was 147.7 mm Hg and 54 month follow-up was 131.7 mm Hg ( -16.0 mm Hg, p<.001). The differential reduction by study arm in SBP from baseline to 54 months was -1.0 mm Hg (95% CI: -5.4 to 3.4, p=0.63). For TI patients, baseline DBP was 84.4 mm Hg and 54 month follow-up was 77.8 (-6.6 mm Hg, p<.001). For UC patients, baseline DBP was 85.1 mm Hg and 54 month follow-up was 79.1 mm Hg (-6.0 mm Hg, p<.001). The differential reduction by study arm in DBP from baseline to 54 months was -0.6 mm Hg (95% CI: -3.5 to 2.4, p=0.67). SBP and DBP results from routine clinical measurements closely approximated the pattern of results from research clinic measurements. Conclusion: Significant BP reductions in the TI arm relative to UC were no longer seen at 54 month follow-up. To maintain intervention benefits over a longer period of time additional intervention is needed.

scholarly journals Parent-Focused Sexual Abuse Prevention: Results From a Cluster Randomized Trial

2020 ◽  
pp. 107755952096387
Author(s):  
Kate Guastaferro ◽  
John M. Felt ◽  
Sarah A. Font ◽  
Christian M. Connell ◽  
Sheridan Miyamoto ◽  
...  
Keyword(s):  
Sexual Abuse ◽  
Parent Training ◽  
Randomized Trial ◽  
Parenting Behaviors ◽  
Cluster Randomized Trial ◽  
Protective Behaviors ◽  
Significant Group ◽  
Cluster Randomized ◽  
General Parenting

This study tested whether a child sexual abuse (CSA) prevention program, Smart Parents–Safe and Healthy Kids (SPSHK), could be implemented as an additional module in evidence-based parent training and whether the added module might detract from the efficacy of the original program. In a cluster randomized trial, six community-based organizations were randomized to deliver Parents as Teachers (PAT) with SPSHK (PAT+SPSHK) or PAT as usual (PAT-AU). CSA-related awareness and protective behaviors, as well as general parenting behaviors taught by PAT were assessed at baseline, post-PAT, post-SPSHK, and 1-month follow-up. Multilevel analyses revealed significant group by time interactions for both awareness and behaviors ( ps < .0001), indicating the PAT+SPSHK group had significantly greater awareness of CSA and used protective behaviors more often (which were maintained at follow-up) compared to the PAT-AU group. No differences were observed in general parenting behaviors taught by PAT suggesting adding SPHSK did not interfere with PAT efficacy as originally designed. Results indicate adding SPHSK to existing parent training can significantly enhance parents’ awareness of and readiness to engage in protective behavioral strategies. Implementing SPHSK as a selective prevention strategy with at-risk parents receiving parent training through child welfare infrastructures is discussed.

Cluster-randomized trial of early palliative care for patients with metastatic cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 9003-9003 ◽  
Author(s):  
Camilla Zimmermann ◽  
Nadia Swami ◽  
Gary Rodin ◽  
Ian Tannock ◽  
Monika K. Krzyzanowska ◽  
...  
Keyword(s):  
Palliative Care ◽  
Randomized Trial ◽  
Symptom Severity ◽  
Metastatic Cancer ◽  
Symptom Control ◽  
Cluster Randomized Trial ◽  
Satisfaction With Care ◽  
Early Palliative Care ◽  
Cluster Randomized

9003 Background: Patients with metastatic cancer have compromised quality of life (QOL), which tends to worsen towards the end of life. We conducted a cluster-randomized trial of early versus routine palliative care in patients with metastatic cancer, to assess impact on QOL, symptom control and satisfaction with care. Methods: Twenty-four medical oncology clinics were randomized, stratified by tumour site (4 lung clinics, 8 gastrointestinal, 4 genito-urinary, 6 breast, 2 gynecological), to intervention and follow-up (at least monthly) by a palliative care team, or to routine cancer care. Eligible patients had ECOG performance status 0-2 and a clinical prognosis of 6 months to 2 years. Patients completed measures of QOL (FACIT-Sp, including physical, social, emotional, functional and spiritual well-being; range 0-156, with higher scores indicating better QOL), symptom severity (Edmonton Symptom Assessment System; range 0-90, with higher scores indicating worse symptom severity), and satisfaction with care (FAMCARE-P16; score range 16-80) at baseline and monthly for 4 months. The primary outcome was the change in FACIT-Sp at 3 months. The planned sample size was 225 patients per arm, assuming 80% power and a 2-sided significance level of 0.05. Results: From December 2006 to September 2010, 461 patients completed baseline measures (228 intervention, 233 control); 442 patients completed at least one follow-up assessment (mean patients/cluster 18.8±11.6 control, 18.1±12.6 intervention). At 3 months, patients in the intervention group had marginally improved QOL (mean change in intervention vs. control, 1.6±14.5 vs. -2.0±13.6, p=0.07) but not symptom severity (0.1±16.9 vs. 2.1±13.9, p=0.34). At 4 months the change in QOL was more marked (2.5±15.5 vs. -4.0±14.2, p=0.008) and symptom severity was marginally better (-1.3±16.0 vs. 3.2±13.9, p=0.05). Improvement in satisfaction with care was evident at one month (p=0.001) and remained significant at both 3 months (2.3±9.1 vs.-1.8±8.2, p=0.001) and 4 months (3.7±8.6 vs. -2.4±8.3, p<0.001). Conclusions: In patients with metastatic cancer, early palliative care intervention immediately improved satisfaction with care, while QOL and symptom control improved later.

scholarly journals Results of Optimize: A Cluster Randomized Trial of Patient, Family, and Provider Education in Primary Care

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 404-404
Author(s):  
Ariel Green ◽  
Elizabeth Bayliss ◽  
Susan Shetterly ◽  
Melanie Drace ◽  
Jonathan Norton ◽  
...  
Keyword(s):  
Primary Care ◽  
Cognitive Impairment ◽  
Randomized Trial ◽  
Effect Size ◽  
Chronic Conditions ◽  
Cluster Randomized Trial ◽  
Chronic Medications ◽  
Cluster Randomized ◽  
Inappropriate Medications

Abstract Individuals with cognitive impairment frequently have multiple chronic conditions (MCC), increasing their risk for polypharmacy and associated adverse outcomes. Optimizing medications through deprescribing (reducing or stopping the use of inappropriate medications or medications unlikely to be beneficial) may improve outcomes for this population. Optimize was a pragmatic, 12-month cluster-randomized trial of deprescribing in primary care within a not-for-profit integrated delivery system. Participants were age 65+ with dementia or mild cognitive impairment (MCI), 2+ chronic conditions, and 5+ chronic medications. The intervention consisted of a deprescribing educational brochure for patients/caregivers, and Tip Sheets for primary care clinicians. Outcomes were the number of chronic medications and presence of potentially inappropriate medications (PIM). In total, 1,433 patients received, and 1,579 control clinic patients would have been eligible to receive, the intervention (N=3,012). After 6 months, mean estimates of chronic medications were 6.23 in the intervention group and 6.33 in the control group adjusting for baseline counts, age, and gender (p=0.13). Excluding those without complete 90 days follow-up increased the adjusted effect size to 0.14 (p=0.08). In sub-analyses of individuals with 7+ medications at baseline (N= 1,434), the adjusted effect size was 0.19 (p=0.07) at 6 months and 0.21 (p=0.045) when excluding those without complete 90 days’ follow-up. Change in proportions of PIM did not differ between intervention and control groups. An educational intervention for patients, caregivers and clinicians may prompt reductions in chronic medications. The relatively small effect size highlights the complexity of medication management for individuals with dementia or MCI and MCC.

Promoting and maintaining urinary continence: Follow‐up from a cluster‐randomized trial of elderly village women in Bangladesh

2020 ◽  
Vol 39 (4) ◽  
pp. 1152-1161
Author(s):  
Rezaul Haque ◽  
Fardous Kabir ◽  
Kamrun Naher ◽  
Nicola Cherry ◽  
Dianna MacDonald ◽  
...  
Keyword(s):  
Randomized Trial ◽  
Cluster Randomized Trial ◽  
Urinary Continence ◽  
Village Women ◽  
Cluster Randomized
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