--- title: "Risk factors of schistosomiasis in rural China. | Sutter Health" description: "Results support applying analysis approaches that do not require arbitrary model pre-specification in data analysis related to water contact and schistosomiasis" url: "https://www.sutterhealth.org/research/publications/risk-factors-of-schistosomiasis-in-rural-china-1055312701" --- 1. [Home](https://www.sutterhealth.org/) / 2. [Research](https://www.sutterhealth.org/research) / 3. [Research publications](https://www.sutterhealth.org/research/publications) / 4. Risk factors of schistosomiasis in rural China. # Using variable importance measures from causal inference to rank risk factors of schistosomiasis infection in a rural setting in China. Sudat SE, Carlton EJ, Seto EY, Spear RC, & Hubbard AE. _Epidemiol Perspect Innov. 7:3. doi: 10.1186/1742-5573-7-3._ 2010-07-14 ## Abstract BACKGROUND: Schistosomiasis infection, contracted through contact with contaminated water, is a global public health concern. In this paper we analyze data from a retrospective study reporting water contact and schistosomiasis infection status among 1011 individuals in rural China. We present semi-parametric methods for identifying risk factors through a comparison of three analysis approaches: a prediction-focused machine learning algorithm, a simple main-effects multivariable regression, and a semi-parametric variable importance (VI) estimate inspired by a causal population intervention parameter. RESULTS: The multivariable regression found only tool washing to be associated with the outcome, with a relative risk of 1.03 and a 95% confidence interval (CI) of 1.01-1.05. Three types of water contact were found to be associated with the outcome in the semi-parametric VI analysis: July water contact (VI estimate 0.16, 95% CI 0.11-0.22), water contact from tool washing (VI estimate 0.88, 95% CI 0.80-0.97), and water contact from rice planting (VI estimate 0.71, 95% CI 0.53-0.96). The July VI result, in particular, indicated a strong association with infection status - its causal interpretation implies that eliminating water contact in July would reduce the prevalence of schistosomiasis in our study population by 84%, or from 0.3 to 0.05 (95% CI 78%-89%). CONCLUSIONS: The July VI estimate suggests possible within-season variability in schistosomiasis infection risk, an association not detected by the regression analysis. Though there are many limitations to this study that temper the potential for causal interpretations, if a high-risk time period could be detected in something close to real time, new prevention options would be opened. Most importantly, we emphasize that traditional regression approaches are usually based on arbitrary pre-specified models, making their parameters difficult to interpret in the context of real-world applications. Our results support the practical application of analysis approaches that, in contrast, do not require arbitrary model pre-specification, estimate parameters that have simple public health interpretations, and apply inference that considers model selection as a source of variation. [PubMed abstract](https://www.ncbi.nlm.nih.gov/pubmed/20626918) ![Sylvia Sudat, Ph.D.](https://dyn.mktgcdn.com/p/2AHRaDJwevdbwzC2ecrwY3nYIxbiqxd9NbpxBlI8Kpk/fit=crop,gravity=auto,dpr=2,width=188,height=250,quality=100) Sylvia Sudat, Ph.D. Principal investigator [View profile](https://www.sutterhealth.org/research/investigators/sylvia-sudat-phd-1049681027) ## Research topics - [Biostatistics](https://www.sutterhealth.org/research-search-results?query=%22%5C%22Biostatistics%5C%22%22) - [Environmental Exposure](https://www.sutterhealth.org/research-search-results?query=%22%5C%22Environmental+Exposure%5C%22%22) - [Infectious Disease](https://www.sutterhealth.org/research-search-results?query=%22%5C%22Infectious+Disease%5C%22%22) ## Related publications [View all publications](https://www.sutterhealth.org/research-search-results?verticalKey=research_publication) - Publication ### [Causal inference and prediction in health studies: environmental exposures and schistosomiasis, HIV-1 genotypic susceptibility scores and virologic suppression, and risk of hospital readmission for heart failure patients.](https://www.sutterhealth.org/research/publications/causal-inference-and-predication-in-three-health-studies-1055312735) Sudat, S. UC Berkeley. ProQuest ID: Sudat\_berkeley\_0028E\_12729. Merritt ID: ark:/13030/m5xw4pw5. Retrieved from https://escholarship.org/uc/item/9z03362s 2012 Jun 01 - Publication ### [Comparison of dynamic block randomization and minimization in randomized trials: a simulation study.](https://www.sutterhealth.org/research/publications/block-randomization-minimization-randomized-trials-1055312663) Xiao L, Lavori PW, Wilson SR, Ma J. Clin Trials. 8(1):59-69. doi: 10.1177/1740774510391683. 2011 Feb 01 - Publication ### [Factors contributing to variability of quantitative viral PCR results in proficiency testing samples: a multivariate analysis.](https://www.sutterhealth.org/research/publications/variability-of-quantitative-viral-pcr-results-test-samples-1055312782) Hayden RT, Yan X, Wick MT, Rodriguez AB, Xiong X, Ginocchio CC, Mitchell MJ, Caliendo AM; College of American Pathologists Microbiology Resource Committee. J Clin Microbiol. 50(2):337-45. doi: 10.1128/JCM.01287-11. Epub 2011 Nov 23. 2012 Feb 01 - Publication ### [Watering regime and green roof substrate design affect Sedum plant growth.](https://www.sutterhealth.org/research/publications/water-regime-green-roof-substrate-on-sedum-growth-1055312957) VanWoert ND, Rowe DB, Rugh CL, Xiao L. HortSci. 40(3):659-664. 2005 Jun 01 - Publication ### [Green roof storm water retention: effects of roof surface, slope, and media depth.](https://www.sutterhealth.org/research/publications/green-roof-stormwater-retention-1055312932) VanWoert ND, Rowe DB, Andresen JA, Rugh CL, Fernandez RT, Xiao L. J Environ Qual. 34(3):1036-44. Print 2005 May-Jun. 2005 May 11 [View all publications](https://www.sutterhealth.org/research-search-results?verticalKey=research_publication) ```json {"@context":"https://schema.org","@type":"MedicalOrganization","name":"Sutter Health","@id":"https://www.sutterhealth.org/#medicalorganization","url":"https://www.sutterhealth.org","logo":"https://www.sutterhealth.org/static/images/sutter-health-logo.svg","address":{"@type":"PostalAddress","streetAddress":"2200 River Plaza Drive","addressLocality":"Sacramento","addressRegion":"CA","postalCode":"95833","addressCountry":"US"},"areaServed":{"@type":"AdministrativeArea","name":"California"},"sameAs":["https://www.facebook.com/SutterHealth","https://www.instagram.com/sutterhealth/","https://x.com/SutterHealth","https://www.youtube.com/sutterhealth","https://www.linkedin.com/company/sutter-health","https://en.wikipedia.org/wiki/Sutter_Health"]} ``` ```json {"@context":"https://schema.org","@type":"BreadcrumbList","@id":"https://www.sutterhealth.org/research/publications/risk-factors-of-schistosomiasis-in-rural-china-1055312701#breadcrumblist","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://www.sutterhealth.org/"},{"@type":"ListItem","position":2,"name":"Research","item":"https://www.sutterhealth.org/research"},{"@type":"ListItem","position":3,"name":"Research publications","item":"https://www.sutterhealth.org/research/publications"},{"@type":"ListItem","position":4,"name":"Risk factors of schistosomiasis in rural China."}]} ``` ```json {"@context":"https://schema.org","@type":"MedicalScholarlyArticle","@id":"https://www.sutterhealth.org/research/publications/risk-factors-of-schistosomiasis-in-rural-china-1055312701#medicalscholarlyarticle","name":"Using variable importance measures from causal inference to rank risk factors of schistosomiasis infection in a rural setting in China.","headline":"Risk factors of schistosomiasis in rural China.","abstract":"BACKGROUND: Schistosomiasis infection, contracted through contact with contaminated water, is a global public health concern. 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The July VI result, in particular, indicated a strong association with infection status - its causal interpretation implies that eliminating water contact in July would reduce the prevalence of schistosomiasis in our study population by 84%, or from 0.3 to 0.05 (95% CI 78%-89%). CONCLUSIONS: The July VI estimate suggests possible within-season variability in schistosomiasis infection risk, an association not detected by the regression analysis. Though there are many limitations to this study that temper the potential for causal interpretations, if a high-risk time period could be detected in something close to real time, new prevention options would be opened. Most importantly, we emphasize that traditional regression approaches are usually based on arbitrary pre-specified models, making their parameters difficult to interpret in the context of real-world applications. 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