Evidence for long-term efficacy of a membrane filtration device in rural villages in Ghana
Bibliographic record
Abstract
Drinking water contaminated by pathogenic micro-organisms increases the risk of infectious gastrointestinal disease which could potentially lead to acute kidney injury and even death, particularly amongst the young and the elderly. Earlier studies have shown a substantial reduction in the incidence of diarrheal disease over a period of one year using a polysulfone membrane water gravity-powered water filtration device. The current report is a continuation of these studies to assess the long-term effects of the innovative method on diarrheal incidence rates over a 4-year follow-up period. This follow-up study monitored the trend of self-reported diarrheal events in all households in the previously studied villages for 5 months, in the last half of each study year, using the same questionnaire utilized in the earlier study. Three villages that had no device yet installed served as controls. We computed monthly diarrheal incidence rates for all study years (standardized to per 100 person-months) and compared these to the pre-device incidence rate in 2018 and in the control group, using the Wilcoxon rank sum exact test. The average diarrheal incidence rates of 1.5 p100pm in 2019, 2.19 p100pm in 2021, and 0.54p100pm in 2022 were significantly different from an earlier study that reported 17.8 p100pm rates before the devices were installed in 2018, (all p-values < 0.05). Concomitantly, self-reported diarrheal infections were substantially higher in the "control villages" not yet having the filtration device installed (80.9, 77.6, and 21.5 per 100 pm). The consistent and large reduction in diarrhea incidence documents the long-term efficacy of the use of the membrane filtration device. This simple water purification method using gravity flow improves public health in remote regions with limited resources.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".