The Role of Water, Sanitation and Hygiene (WaSH) Interventions on Health and Behavioral Outcomes during Humanitarian Crisis: A Systematic Review and Meta-Analysis.

Background: In humanitarian crises, water, sanitation and hygiene interventions are critical for the survival of people. However, strong evidence-based information is still limited. In order to describe the quantity and quality of current evidence, we conducted an evidence gap map provides a visual overview, highlighting areas lacking evidence.

Methods: According to developed inclusion and exclusion criteria, a systematic literature search was conducted to find related systematic reviews and meta-analyses. The databases, including PubMed, Web of Science, SCOPUS and Cochrane were searched using search strings from 2000 until 2021. Characteristics of the included reviews were extracted and summarized. Two persons evaluated methodological quality independently using the AMSTAR tool. Invite a third person to solve any discrepancies.

Results: This study revealed seven systematic reviews, including one meta-analysis. One study was of high quality, four of medium, and two of low quality. A total of 272 primary studies were included with a median value of 38.8 (range, 6-106) which deeply analyzed for data extraction. Cross-sectional, case-control, and qualitative case studies were the most used study designs. Diarrheal diseases were the most reported outcomes representing 46% of the impact evaluations. Cholera outbreaks account for 43% of a crisis context. The research gaps were insufficient reporting of some interventions with related outcomes and the geographical distribution of current evidence.

Conclusion: There is a limitation in current evidence represented by a lack of high-quality and experimental studies investigate the impact of water, sanitation and hygiene (WaSH) interventions on health and behavioral outcomes in humanitarian sittings.