Health impact of water supply and sanitation projects in Northern Pakistan

It is well established that lack of access to safe water, inadequate sanitation, and poor hygiene practices are responsible for the high prevalence of preventable diseases in developing countries. According to WHO/UNICEF, 4 billion cases of diarrhoea are reported in the world every year, with 2.2 million deaths annually, mostly among children under five. However, it has always been a major challenge to quantify the extent of impact of water, sanitation, and hygiene education interventions due to methodological complexities and confounding variables (Briscoe, Feachem, and Rahman, 1985; Cairncross, 1990; Esrey et al., 1991; Gorter and Sandiford, 1997). Major methodological flaws identified included the problems of (i) comparability of treatment and control groups, (ii) sample size required, (iii) misclassification bias, and (iv) recall bias in ascertaining disease status amongst others. Measurement of the impact of water, sanitation, and hygiene interventions becomes even more difficult, when implementing agencies set objectives/targets based on health impact e.g., reduction of water and sanitation related diseases. These difficulties stem from lack of resources both human and financial, operational difficulties, time limitation, and inability in implementing proposed plans due to factors falling beyond organisational control. The Water and Sanitation Extension Programme (WASEP) of the Aga Khan Planning and Building Service (AKPBS) is one implementing agency in Pakistan whose major objective is to reduce diarrhoeal diseases. WASEP has been implementing water and sanitation projects in northern Pakistan since 1998. This paper will describe how health impact is being measured at WASEP, and share issues and problems encountered in the process.