A simple index to measure hygiene behaviours

BACKGROUND: Spot checks are becoming a popular method to assess hygiene behaviours; however, little is known about their repeatability or predictability. We evaluated the within-household repeatability of hygiene indices created from spot checks and their ability to predict incidence of diarrhoea in young Guatemalan children. METHODS: We observed hygiene behaviours in 588 households in four rural Guatemalan communities over 36 months. Four indices related to drinking water (DWI; score = 0-3), food (FI; score = 0-3), personal hygiene (PHI; score = 0-3), and domestic household hygiene (DHI; score = 0-6) and one summary hygiene index (SHI; range 0-15) were created. Morbidity of 694 children aged birth to 36 months living in the study households was assessed using biweekly recall. Intraclass correlation coefficients were calculated to assess within-household repeatability; the generalized estimating equations approach was employed to analyse diarrhoea morbidity. RESULTS: Households were observed a mean of 22.1 +/- 11.2 times. All indices decreased with duration of follow-up (SHI = -0.67 +/- 0.05 points/year; WI = -0.04 +/- 0.01; FI = -0.07 +/- 0.01; PHI = -0.21 +/- 0.01; DHI = -0.37 +/- 0.02; all P < 0.05). Intraclass correlations were low to moderate (SHI = 0.35-0.51; DWI = 0.17-0.21; FI = 0.16-0.18; PHI = 0.27-0.32; DHI = 0.27-0.38). Six separate spot checks would be needed to estimate a household's underlying level of hygiene within 20%. SHI and PHI scores were inversely associated with diarrhoea morbidity (both P < 0.05). CONCLUSIONS: Hygiene indices created using spot checks can be a rapid and efficient method for assessing hygiene and useful for predicting diarrhoea morbidity in young children. Multiple measures are required to accurately estimate the true hygiene pattern of a household.