Different methods of assessing adherence
| Method | Accuracy | [Ref.] |
| Self-report | Highly inaccurate | [11, 20, 21] |
| Validated anonymous questionnaire | Highly inaccurate | [11, 22] |
| Physician or asthma nurse assessment | Highly inaccurate | [3] |
| Pharmacy refill rate | Inaccurate | [3, 21] |
| Returned inhalers: canister weighing, dose counters | Fairly accurate | [21] |
| Pharmacological methods: blood/urine drug levels | Fairly accurate | [23] |
| Exhaled nitric oxide measurement | Inaccurate | [24] |
| Electronic monitoring | Highly accurate | [3, 21, 25] |