Difficulties in
scaling up proven effective interventions include weakness in
delivery systems,inappropriate delivery strategies, limited
resources, difficulties in estimating resource requirements and
spending those resources effectively and efficiently, and the short
timeframe for planning, implementing, integrating, and sustaining
the interventions
. However, historically, large scale interventions have not been rigorously evaluated, and their health
impact is unclear
. In
Myanmar, the National Sanitation Week and Social Mobilization for
Sanitation and Hygiene programme contributed to a significant
increase in access to sanitary means of excreta disposal and
handwashing with soap and water after defecation, but no health
outcome was measured
An evaluation of
a water, sanitation and hygiene programme implemented in
Pakistan showed a significant reduction in diarrhea, but this evaluation did not capture the interim behaviors that lead to reduction
in diarrhea