Development and reliability of a quantitative personal hygiene assessment tool

Abstract

Personal hygiene practices, including facewashing and handwashing, reduce transmission of pathogens, but are difficult to measure. Using color theory principles, we developed and tested a novel metric that generates quantitative measures of facial and hand cleanliness, proxy indicators of personal hygiene practices. In this cross-sectional study, conventional qualitative cleanliness metrics (e.g., presence or absence of nasal and ocular discharge, dirt under nails or on finger pads and palms) were also recorded. We generated Gwet’s agreement coefficients to determine the inter-rater reliability of novel and conventional metrics between various rating groups, where appropriate, including two non-blinded raters, non-blinded vs. blinded raters, three blinded raters, and blinded vs. computer raters. Inter-rater reliability of the novel metric was high across all rating groups, ranging from 0.98 (95% CI: 0.97, 0.99) to 0.90 (95% CI: 0.90, 0.91) for facial cleanliness, and 0.97 (95% CI: 0.96, 0.98) to 0.92 (95% CI: 0.91, 0.93) for hand cleanliness. Our novel metric generates more nuanced data than conventional qualitative metrics, and allows for quantifiable assessments of facial and hand cleanliness.

Facial cleanliness indicators by time of day: results of a cross-sectional trachoma prevalence survey in Senegal

“…This highlights the issue that environmental confounders can influence the reliability of facial cleanliness indicators, and is consistent with findings from others that study location affects the proportion of children with certain dirty face indicators, in particular flies on the face [ 8 , 9 ]. Nasal and ocular discharge are no longer capable of being reliable face washing indicators when children cry in anticipation of being examined [ 9 , 10 , 26 ], and dirt/dust/food on the face is also too context-dependent to enable between-setting comparisons [ 8 – 10 ].…”

“…More objective and quantitative measures of facial cleanliness have been proposed, such as the qPHAT methodology that enables raters to match the colour on face wipes with an 11-point colour scale [ 10 ]. However, the published evaluation of this methodology’s reliability was not intended to assess its ability to establish recent face cleaning.…”

“…However, inter-grader variability was prevented by using the same grader throughout. We did not separate out dry and wet nasal discharge, which could have added to the literature on whether dry nasal discharge is a more reliable measure of face washing than wet discharge [ 8 , 10 ]. We conducted examination at a central village point, whereas in routine population-based prevalence surveys, teams typically go house-to-house [ 7 ].…”

“…However, non-participant observation of washing practices, such as that conducted in a school-based face washing programme for trachoma [ 31 ], is not practical during a cross-sectional survey, and may in itself influence behaviour. Herein lies the challenge: if there is no reliable and practical indicator, effective face washing interventions cannot be developed, monitored or evaluated [ 10 ].…”

“…Since presence of active trachoma is measured directly in trachoma population-based prevalence surveys [ 7 ], the primary purpose of measuring clean faces is to determine the success of face washing campaigns. Various indicators for measuring an unclean face exist (which can be used in isolation, or in conjunction with each other) [ 8 – 10 ], including the presence of ocular or nasal discharge [ 11 ], dust/dirt on the face [ 12 , 13 ], and food on the face [ 14 ]. In addition, the presence of flies on the face can be considered an indirect measure of an unclean face, with M. sorbens obtaining nutrition and liquid from ocular and nasal discharge [ 15 ].…”