Randomised Trial — Household Filters and Diarrhoea
A field RCT reporting reduced childhood diarrhoea among households using point-of-use filters.
SDG 6 Clean Water & SanitationSDG 3 Good Health & Well-beingWhat is it?
A randomised controlled trial in which households were assigned to receive a point-of-use filter or not, and diarrhoeal illness was tracked over months. It represents the primary-trial evidence base.
Why does it matter?
Randomisation reduces confounding, so such trials are a stronger basis for causal claims about filters than observational studies.
How does it work?
Households are randomly allocated to intervention or control; outcomes (reported diarrhoea, sometimes water quality) are compared between arms over the follow-up period.
Who benefits?
Program designers and funders who need causal evidence of effect before scaling an intervention.
Who may be disadvantaged?
Findings from one setting may not transfer; a trial in a specific climate and culture can mislead if applied uncritically elsewhere.
What evidence exists?
This trial reports a statistically significant reduction in child diarrhoea in the filter arm, in line with much of the household-water-treatment literature.
What tradeoffs exist?
Unblinded trials with self-reported outcomes risk courtesy and reporting bias, which can inflate apparent effects — a key reason to read the systematic review.
Common misconceptions
A single positive trial is not proof of universal effectiveness; effect sizes vary and depend heavily on sustained, correct use.
What you can do next
Read the Cochrane systematic review node, which pools many such trials and discusses their biases.