Savilahti 2000.
| Methods | Controlled before‐after study | |
| Participants | The study group consisted of 397 children aged 7 to 12 in a mould‐damaged school and a control group of 192 non‐exposed children of the same age in a control school in Finland | |
| Interventions | Thorough remediation of the moisture‐damaged school | |
| Outcomes | Building: investigation of the buildings. Microbiological samples from the air, surfaces and materials Participants: occurrence of respiratory infections (common cold, tonsillitis, otitis, sinusitis, bronchitis) |
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| Notes | The moisture damage was verified using microbiological samples from the air, surfaces and materials. Following renovation, new samples were taken | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Not blinded |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | Not blinded |
| Unplanned subgroup analyses (16) | Low risk | No unplanned subgroup analyses |
| Follow‐up (17) | Low risk | Follow‐up time of 1 year |
| Compliance (19) | Unclear risk | Compliance unclear |
| Valid outcome measures (20) | Low risk | Medical records were used in addition to the questionnaire |
| Selection bias (population) (21) | Low risk | Participants and controls were recruited from the same population |
| Selection bias (time) (22) | Low risk | The questionnaires were sent to both the intervention and control group at the same time |
| Random sequence generation (selection bias) | High risk | Not randomised |
| Allocation concealment (selection bias) | High risk | Not concealed |
| Adjustment for confounding (25) | Low risk | Distribution of known confounders in the intervention and control group was described |
| Incomplete outcome data (26) (attrition bias) | Low risk | Response rate to the second questionnaire was 81% in the intervention school and 100% in the control school |