Primary School Deworming — Kenya

Summary

The Kenya deworming study found that mass treatment with a cheap, safe drug increased school participation substantially — and that the effects persisted into adulthood as higher earnings. The $3.50 cost per additional year of schooling made it one of the most cost-effective education interventions documented. The study became a cornerstone of evidence-based development and triggered a global scale-up. Subsequent reanalysis and replication have produced more modest estimates, and a Cochrane review found weaker evidence of general health benefits — but the cost-effectiveness case for deworming in high-prevalence areas remains strong.

Research question

"Does mass deworming treatment in primary schools improve attendance and learning outcomes?"

Methodology

Result

Positive

School participation: +7.5 percentage points; cost per additional year of schooling: $3.50; long-run earnings for treated cohort: +14% at age 20

Evidence strength

Strong

Randomized controlled trial with large sample.

Replication status

Partially replicated