Meklin 2005a.

Methods	Controlled before‐after study
Participants	School children (7 to 13 yrs) in a mould‐damaged school (before repairs 414 pupils and 408 after repairs), were compared to children (7 to 14) in a non‐damaged school (208 pupils in the beginning and 238 in the final survey) in Finland
Interventions	Extensive renovation of the school building: structures were opened and renewed, land‐drains, drain‐, heating and water pipes were renewed, all coating materials were renewed, ventilation was installed, alteration from natural ventilation to mechanical exhaust and air supply. A thorough cleaning of the school
Outcomes	Buildings: self reported draft, insufficient ventilation, humid indoor air, mould odour, other unpleasant odour, dust or dirt, airborne bacteria and fungi Participants: self reported respiratory and asthma‐related symptoms
Notes	Results are presented in 2 different articles
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)	Unclear risk	No data dredging
Follow‐up (17)	Low risk	Follow‐up time up to 5 years
Compliance (19)	Unclear risk	Compliance unclear
Valid outcome measures (20)	Unclear risk	Questionnaire of subjective symptoms
Selection bias (population) (21)	High risk	Participants and controls were from the same population but in the fully repaired school the attention to the problems seemed to be greater than elsewhere
Selection bias (time) (22)	Low risk	The questionnaires were sent to the intervention and control group at the same time
Random sequence generation (selection bias)	High risk	Not done
Allocation concealment (selection bias)	High risk	Not done
Adjustment for confounding (25)	Low risk	Age and prevalence of smoking was reported
Incomplete outcome data (26) (attrition bias)	Low risk	Loss to follow‐up reported