| Methods |
Prospective cohort study conducted in a school of Chicago, USA, to evaluate the effectiveness of a handwashing programme in reducing the absenteeism caused by flu‐like illness. The school was located in a predominantly white, middle to upper middle class suburb. All 4 kindergarten and 5 first‐grade classes were included in the study. No significant differences were found between participating classes for size, male‐female ratio, percentage of low‐income students, or students with chronic health problems. Teachers were surveyed to determine classroom handwashing activities. The influenza season usually occurs during December and January. The handwashing programme was planned for presentation just prior to this time. The effectiveness of the programme was determined by comparing absentee rates among participants and non‐participating classes (the control group). Absentee rates were determined by reviewing the computerised daily school absence logs. Entries that listed flu‐like symptoms were counted. A take‐home handwashing chart was also given to each student to encourage follow‐through with handwashing at home |
| Participants |
199 children of kindergarten and first grade schools |
| Interventions |
Handwashing and educational programme versus no intervention |
| Outcomes |
Laboratory: no
Effectiveness: flu‐like illness
Safety: n/a
Absenteeism from influenza‐like illness was approximately double in the control arm (P = 0.01) |
| Notes |
Risk of bias: medium
Notes: the authors concluded that handwashing education can decrease absenteeism even among kindergarten and first grade students. This study did not control for health and hygiene practices at home or exposure to ILI outside of school. Furthermore the student population at the school was generally healthy, probably because families were able to provide adequate health and hygiene resources. Another problem of the study is that the flu season was later than usual (February), and this represented a confounding variable. The teacher surveys indicated problems with handwashing facilities |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
N/A |
| Allocation concealment (selection bias) |
Unclear risk |
N/A |
| Blinding (performance bias and detection bias)
All outcomes |
Unclear risk |
N/A |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
N/A |
| Selective reporting (reporting bias) |
Unclear risk |
N/A |
