Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
International Centre for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh.
Am J Trop Med Hyg. 2019 Jul;101(1):51-58. doi: 10.4269/ajtmh.18-0872.
To explore the consistency in impact evaluation based on reported diarrhea, we compared diarrhea data collected through two different surveys and with observed diarrhea-associated hospitalization for children aged ≤ 5 years from a non-blinded cluster-randomized trial conducted over 2 years in urban Dhaka. We have previously reported that the interventions did not reduce diarrhea-associated hospitalization for children aged ≤ 5 years in this trial. We randomly allocated 90 geographic clusters comprising > 60,000 low-income households into three groups: cholera vaccine only, vaccine plus behavior change (cholera vaccine and handwashing plus drinking water chlorination promotion), and control. We calculated reported diarrhea prevalence within the last 2 days using data collected from two different survey methods. The "census" data were collected from each household every 6 months for updating household demographic information. The "monthly survey" data were collected every month from a subset of randomly selected study households for monitoring the uptake of behavior change interventions. We used binomial regression with a logarithmic link accounting for clustering to compare diarrhea prevalence across intervention and control groups separately for both census and monthly survey data. No intervention impact was detected in the census (vaccine only versus control: 2.32% versus 2.53%; = 0.49; vaccine plus behavior change versus control: 2.44% versus 2.53%; = 0.78) or in the vaccine only versus control in the monthly survey (3.39% versus 3.80%; = 0.69). However, diarrhea prevalence was lower in the vaccine-plus-behavior-change group than control in the monthly survey (2.08% versus 3.80%; = 0.02). Although the reasons for different observed treatment effects in the census and monthly survey data in this study are unclear, these findings emphasize the importance of assessing objective outcomes along with reported outcomes from non-blinded trials.
为了探索基于报告腹泻的影响评估的一致性，我们比较了在为期两年的达卡市非盲随机对照试验中收集的两种不同调查方法和观察到的 5 岁以下儿童腹泻相关住院的数据。我们之前报道过，在该试验中，干预措施并未减少 5 岁以下儿童腹泻相关住院。我们将 90 个地理集群（包含 6 万多个低收入家庭）随机分配到三组：仅霍乱疫苗、疫苗加行为改变（霍乱疫苗和洗手加饮用水氯化促进）和对照组。我们使用从两种不同调查方法收集的数据计算了最近两天内报告的腹泻患病率。“普查”数据每 6 个月从每个家庭收集一次，用于更新家庭人口统计信息。“每月调查”数据每月从随机选择的部分研究家庭收集，用于监测行为改变干预措施的采用情况。我们使用二项式回归和对数链接，对普查和每月调查数据分别在干预组和对照组之间比较腹泻患病率，同时考虑了聚类。在普查中未检测到干预的影响（仅疫苗组与对照组：2.32%比 2.53%； = 0.49；疫苗加行为改变组与对照组：2.44%比 2.53%； = 0.78）或在每月调查中仅疫苗组与对照组之间（3.39%比 3.80%； = 0.69）。然而，在每月调查中，疫苗加行为改变组的腹泻患病率低于对照组（2.08%比 3.80%； = 0.02）。尽管本研究中普查和每月调查数据中观察到的治疗效果不同的原因尚不清楚，但这些发现强调了在非盲试验中评估客观结局与报告结局的重要性。
