| Asthma definition | Studies n | References# |
| Bronchial hyperresponsiveness AND current wheeze | 1 | [S12] |
| Bronchial hyperresponsiveness AND current wheeze or current nocturnal cough | 1 | [S23] |
| Bronchial hyperresponsiveness AND history of asthma and at least one of the following: reported dyspnoea, chest tightness or wheezing in the previous 12 months | 1 | [S17] |
| Bronchial hyperresponsiveness AND ≥1 episode of wheezing in the previous 12 months | 3 | [S34¶, S64, S87] |
| Bronchial hyperresponsiveness AND (current complaints or complaints during the previous 12 months AND/OR use of asthma medication (use of β2-agonists or inhaled corticosteroids currently or in the last 12 months)) | 1 | [S40] |
| Bronchial hyperresponsiveness AND doctor diagnosed asthma AND (at least two respiratory symptoms (cough, wheezing, dyspnoea, and nocturnal cough, wheezing, dyspnoea) or a history of recurrent asthma attacks) | 1 | [S83] |
| Bronchial hyperresponsiveness AND doctor's diagnosis of asthma ever and asthma symptoms in the previous 12 months | 1 | [S48] |
| Bronchial hyperresponsiveness AND current wheeze (wheezing, whistling, nocturnal cough or exercise-induced wheeze in the last 12 months) | 1 | [S70] |
| A ≥15% increase in peak flow after inhaled salbutamol AND (episodic wheezing, episodic dyspnoea or successive 3-day nocturnal cough) | 1 | [S82] |
| Based on lung function results, history of the disease and physical examination | 3 | [S110, S45, S69] |
| Doctor's diagnosis of asthma ever | 12 | [S51, S120, S86, S103, S77, S99, S98, S104, S32, S88, S95, S27] |
| Doctor's diagnosis of asthma at this moment | 4 | [S61, S71, S38, S5] |
| Doctor's diagnosis of asthma (unspecified when) | 9 | [S4, S28, S108, S111, S119, S59, S37, S15, S94] |
| Doctor diagnosed asthma (in a certain period) | 2 | [S67, S68] |
| Doctor diagnosed asthma ever AND current wheeze (in the last 3 yrs) | 1 | [S74] |
| Doctor's diagnosis of asthma ever and asthma symptoms in the previous 12 months | 5 | [S13, S33, S53, S85, S106¶] |
| Doctor's diagnosis of asthma ever AND ≥1 episode of wheezing in the previous 12 months | 4 | [S6, S50, S41, S89] |
| Doctor's diagnosis of asthma (unspecified when) and ≥1 episode of wheezing in the previous 12 months | 3 | [S14, S52, S76] |
| Doctor diagnosed asthma AND ≥1 exacerbation in previous 12 months | 2 | [S114, S107] |
| Doctor diagnosed asthma AND (asthma symptoms and/or wheezing ever) | 1 | [S101] |
| Doctor diagnosed asthma AND (≥1 episode of asthma during the previous year or >3 episodes of wheezing during the previous year) | 1 | [S105] |
| Doctor diagnosed asthma AND wheeze in the last year AND sleep disturbance due to wheeze in the last year AND objective atopy | 1 | [S100] |
| Doctor diagnosis of asthma ever AND having asthma in a given time period (16–18 yrs) AND experiencing any asthma symptoms during the period | 1 | [S39] |
| Doctor diagnosed asthma AND wheeze (unspecified when) AND current use of asthma medication | 1 | [S66] |
| Doctor diagnosis of asthma AND asthma symptoms (wheeze and/or nocturnal cough in the absence of an obvious respiratory infection) in the past 12 months AND use of asthma medication in the past 12 months | 1 | [S62] |
| Doctor diagnosis of asthma ever AND (symptoms of asthma or use of asthma medication in the previous 12 months) | 6 | [S1, S81, S56, S75, S84, S96¶] |
| Doctor diagnosed asthma (ever) AND more than one illness in the previous 12 months or one illness and 1) ever interrupted sleep or 2) any medication in the last 12 months or 3) overnight hospital stay in the last 12 months | 1 | [S118] |
| Physician diagnosed asthma, observed wheezing, and/or prescription of asthma medication during the time period when the child was between 6 and 8 yrs of age (from medical records): parental reports of occurrence of asthma collaborated the medical record data | 1 | [S91] |
| Physician diagnosed asthma AND wheeze or asthma symptoms reported on ≥2 questionnaires | 1 | [S97] |
| Doctor diagnosed asthma AND (wheeze in the past 12 months or use of asthma medication in the past 12 months) | 2 | [S2, S25¶] |
| Answers “Yes” to “Has your child had asthma?” AND “Yes” to “Was asthma diagnosed or treated by a physician?” AND ((asthma symptoms (“usual cough”, “chest wheezy or whistling” or “attacks of wheezing with shortness of breath”) during the past year OR has used asthma medication during the 3 previous months) | 1 | [S60] |
| (Two or more episodes of wheezing accompanied by dyspnoea that had ever been given the diagnosis of asthma by a physician) AND (the occurrence of asthmatic attacks or the need for any medication for asthma during the past 2 yrs) | 1 | [S72] |
| Asthma at this moment | 1 | [S22] |
| Asthma ever | 7 | [S8, S20, S49, S30, S54, S46, S92¶] |
| Asthma in the previous 12 months | 4 | [S43, S90, S11, S29¶] |
| Asthma in the previous 24 months | 1 | [S112] |
| “Does your child have long-term illnesses?” Asthma was one of the main concerns listed OR children that had ever been hospitalised due to asthma | 2 | [S113, S102] |
| Asthma ever AND asthma in the last 6 months | 2 | [S10, S35] |
| Asthma (unspecified when) AND symptoms in the previous 12 months | 1 | [S79] |
| Asthma ever AND wheezing or whistling in the chest in the past 12 months | 1 | [S115] |
| Admitted to hospital with primary diagnosis of asthma | 1 | [S55] |
| Diagnosis of asthma AND (wheezy symptoms (i.e. child's chest sounding wheezy or whistling occasionally apart from colds, most days or nights or during the past year) or if asthma medication was used in the past 3 months) | 1 | [S47] |
| Symptoms of wheezing at this moment and symptoms of wheezing in the previous 12 months OR doctors diagnoses asthma | 1 | [S18] |
| ≥3 episodes of bronchial obstruction verified by a physician | 1 | [S109] |
| Wheezing in the previous 12 months in absence of an upper respiratory infection | 1 | [S93] |
| Symptoms of wheezing in the previous 12 months | 4 | [S58, S24, S73, S42] |
| >6 attacks of wheezing in the previous 12 months | 1 | [S65] |
| Use of bronchodilators within the previous year for attacks of wheezing | 1 | [S26] |
| Confirmative answers to the following questions: question 1 and one or more of questions 3, 4, 5, 6 and 7 and one or both questions 8 and 9; question 1 and at least question 11 and confirmed by the medical record of the child; question 1 and at least question 8, 9 and 10 and confirmed by the medical record of the child; question 11 and confirmed by the medical record of the child 1) Has your child ever had wheezing or whistling in the chest? No/Yes 2) Has your child had wheezing or whistling in the chest at any time during the last 12 months No/Yes 3) How many episodes with wheezing has your child had during the last 12 months? none/1–3/4–12/>12 4) During the last 12 months, how often, on average, has your child been disturbed by wheezing? Never/Less than 1 night per week/1 or more nights a week 5) During the last 12 months, had the wheezing of your child ever been so severe that he or she only could say 1 to 2 words between the breathings? No/Yes 6) During the last 12 months, has your child had wheezing in the chest during or after exercise? No/Yes 7) During the last 12 months, has your child had dry cough in the nights without having a cold or an infection? No/Yes 8) Has your child ever had wheezing at any time after 2 years of age? No/Yes 9) Has your child ever had 3 diagnosed episodes of bronchitis before 2 yrs of age? No/Yes 10) Has your child ever had treatment with inhaled lomudal (cromolyn sodium) or inhaled steroids? No/Yes 11) Has your child ever had a diagnosis of bronchial asthma according to a physician? No/Yes | 1 | [S63] |
| Treatment for acute wheezing at a healthcare centre or in hospital in previous 12 months | 1 | [S31¶] |
| ≥3 recurring attacks of bronchial obstruction causing wheezing, coughing or heavy breathing due to external factors such as animal dander, pollen, house dust or food | 1 | [S44] |
| Recurrent wheezing episodes in the child's outpatient medical record (at least one episode of wheezing illness must have occurred in the absence of a respiratory infection) | 1 | [S121] |
| 3 episodes of bronchial obstruction in the previous 12 months verified by a physician | 1 | [S78] |
| Attacks of shortness of breath with wheezing within the preceding 12 months in addition to positive responses to question 2, 3, 4 and/or 5 2) Does your breathing ever sound wheezy or whistling? 3) Do you ever have attacks of shortness of breath with wheezing? 4) Do you experience wheezing, chest tightness, cough or breathlessness with any of the following: at rest, with exertion, with emotional stress, with exposure to cold air, or with chest infections or head cold? 5) Do you experience wheezing after exposure to: dust, fumes, moulds, pollen, food, pets or drugs? | 1 | [S57¶] |
| (Doctor diagnosed asthma (ever) AND symptoms of asthma in previous 12 months) OR three separate episodes of persistent wheezing (≥3 days duration) in the previous 12 months | 1 | [S16] |
| Doctor diagnosed asthma at least once or “asthmatic, spastic or obstructive bronchitis” more than once | 1 | [S19] |
| ≥2 doctor visits for asthma in the previous year OR two prescriptions for any asthma drug (β-agonists, inhaled corticosteroids, cromones of leukotriene receptor antagonists) in the previous year OR one hospitalisation in the previous year | 1 | [S9] |
| Cough at night, ever wheeze, wheeze in the past year, asthma ever diagnosed or asthma treated in the previous 4 weeks | 1 | [S116] |
| At least two of the following criteria 1) Dyspnoea ever, chest tightness ever and/or wheezing ever 2) Doctor's diagnosis of asthma 3) Use of medication (β2-agonist, sodium cromoglycate, corticosteroids, leukotriene antagonists and/or aminophylline) ever | 1 | [S21] |
| Code 493/j45-46 | 1 | [S117] |
| No definition of asthma given | 2 | [S3, S7] |
#: bibliography for these citations is provided in the online supplementary material. ¶: more than one outcome of asthma was given; the most stringent definition is cited in this table. For papers S36, S80 and S122 it was not possible to define the most stringent one, so these definitions are not cited in the table.