1. Grading of the evidence.
| Comparison | Outcome | Risk of bias | Inconsistency | Indirectness | Imprecision | Publication bias | Quality of the evidence |
| House remediation versus no remediation Adults | Asthma‐related symptoms | 2 RCTs (low risk of bias) and 1 CBA study (high risk of bias) | Inconsistent results between the high risk of bias study and the low risk of bias studies | ‐ | ‐ | ‐ | Moderate‐quality evidence |
| Asthma medication | 1 RCT (low risk of bias) | Perceived change in medication inconsistent with the reported use of medication | ‐ | ‐ | ‐ | Moderate‐quality evidence | |
| Respiratory infections | 2 RCTs (low risk of bias) and 1 CBA study (high risk of bias) | ‐ | ‐ | Wide CIs in the high risk of bias study | ‐ | Moderate‐quality evidence | |
| Completed house remediation versus remediation in progress Adults | Asthma‐related symptoms | 1 CBA study (high risk of bias) | ‐ | ‐ | ‐ | Very low‐quality evidence | |
| Office building remediation versus no exposure Adults | Asthma‐related symptoms | 1 CBA study (high risk of bias) | ‐ | ‐ | ‐ | ‐ | Very low‐quality evidence |
| Respiratory symptoms | 1 CBA study (high risk of bias) | ‐ | ‐ | ‐ | ‐ | Very low‐quality evidence | |
| House remediation versus information Children | Asthma‐related symptoms | 1 cRCT (low risk of bias) | ‐ | ‐ | In a mixed model a significant decrease at 10‐month follow‐up | ‐ | Moderate‐quality evidence |
| Number of acute care visits | 1 cRCT (low risk of bias) | ‐ | ‐ | A significant decrease only 6 to 12 months after remediation | ‐ | Moderate‐quality evidence | |
| House remediation versus no remediation Children | Asthma‐related symptoms | 1 CBA study (high risk of bias) | ‐ | ‐ | ? | ‐ | Very low‐quality evidence |
| Respiratory symptoms | 1 CBA study (high risk of bias) | ‐ | ‐ | ? | Very low‐quality evidence | ||
| School remediation versus no exposure Children | Asthma‐related symptoms | 2 CBA study (high risk of bias) | ‐ | ‐ | Wide CIs | ‐ | Very low‐quality evidence |
| Respiratory infections | 1 CBA study (high risk of bias) | ‐ | ‐ | ‐ | ‐ | Very low‐quality evidence | |
| Respiratory symptoms | 2 CBA study (high risk of bias) | ‐ | ‐ | ‐ | ‐ | Very low‐quality evidence | |
| School remediation versus no exposure Adults | Asthma‐related symptoms | 2 CBA studies (high risk of bias) | Inconsistent results | ‐ | Wide CIs | ‐ | Very low‐quality evidence |
| Respiratory infections | 1 CBA study (high risk of bias) | ‐ | ‐ | No control group data | ‐ | Very low‐quality evidence | |
| Respiratory symptoms | 2 CBA studies (high risk of bias) | Inconsistent results | ‐ | Wide CIs | ‐ | Very low‐quality evidence |
CI = confidence interval RCT = randomised controlled trial CBA = controlled before‐after study cRCT = cluster‐randomised controlled trial