Use of interrupted time series methods in the evaluation of health system quality improvement interventions: A methodological systematic review

Background When randomisation is not possible, interrupted time series (ITS) design has increasingly been advocated as a more robust design to evaluating health system quality improvement (QI) interventions given its ability to control for common biases in healthcare QI. However, there is a potential risk of producing misleading results when this rather robust design is not used appropriately. We performed a methodological systematic review of the literature to investigate the extent to which the use of ITS has followed best practice standards and recommendations in the evaluation of QI interventions. Methods We searched multiple databases from inception to June 2018 to identify QI intervention studies that were evaluated using ITS. There was no restriction on date, language and participants. Data were synthesised narratively using appropriate descriptive statistics. The risk of bias for ITS studies was assessed using the Cochrane Effective Practice and Organisation of Care standard criteria. The systematic review protocol was registered in PROSPERO (registration number: CRD42018094427). Results Of 4061 potential studies and 2028 unique records screened for inclusion, 120 eligible studies assessed eight QI strategies and were from 25 countries. Most studies were published since 2010 (86.7), reported data using monthly interval (71.4), used ITS without a control (81) and modelled data using segmented regression (62.5). Autocorrelation was considered in 55 of studies, seasonality in 20.8 and non-stationarity in 8.3. Only 49.2 of studies specified the ITS impact model. The risk of bias was high or very high in 72.5 of included studies and did not change significantly over time. Conclusions The use of ITS in the evaluation of health system QI interventions has increased considerably over the past decade. However, variations in methodological considerations and reporting of ITS in QI remain a concern, warranting a need to develop and reinforce formal reporting guidelines to improve its application in the evaluation of health system QI interventions. © Author(s) 202

Household food insecurity and dietary diversity as correlates of maternal and child undernutrition in rural Cambodia

OBJECTIVES: To assess household food insecurity and dietary diversity as correlates of maternal and child anthropometric status and anemia in rural Cambodia. METHODS: Trained interviewers administered a survey to 900 households in four rural districts of Prey Veng, Cambodia. The Household Food Insecurity Access Scale (HFIAS) and Household Dietary Diversity Score (HDDS) were used to assess household food insecurity and dietary diversity. The height, weight and hemoglobin concentration of the mother and youngest child under 5 years in each household were measured. Multivariate logistic regression models were constructed to assess the association between household food insecurity and dietary diversity, and child stunting and wasting, maternal thinness, maternal and child anemia. RESULTS: The mean (s.d.) HFIAS and HDDS scores were 5.3 (3.9) and 4.7 (1.6), respectively. The respective prevalences of mild, moderate and severe food insecurity were 33, 37 and 12%. Maternal thinness, child stunting and child wasting were present in 14.6, 25.4 and 8.1% of respondents, respectively. The risk of maternal thinness, but not child stunting or wasting, increased as the severity of household food insecurity increased. Household food insecurity was also positively associated with maternal, but not child, anemia. Household dietary diversity status was not significantly associated with any of the outcomes we assessed. CONCLUSIONS: Efforts to improve household food security are important as a means of promoting maternal nutritional status; however, additional research is needed to better understand the role of other factors that are driving the burden of child undernutrition in Cambodia

Consumption of novel thiamin-fortified fish sauce improves the thiamin status of rural Cambodian women of childbearing age and their children < 5 years

Kyly C Whitfield, Crystal D Karakochuk, Hou Kroeun, Benny Chan, Mam Borath, Larry D Lynd, Eunice CY Li Chan, David D Kitts, Timothy J Gree