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.