Table 3.
Supportive secondary and explorative outcomes across key follow-up years in subjects with pre-existing asthma
| PRE-EXISTING ASTHMA COHORT | |||||||
|---|---|---|---|---|---|---|---|
| N | % | N | % | OR | 95% CI | p-value | |
| Year 3 | AIT N=10370 | Control N=10370 | AIT vs. Control | ||||
| Asthma treatment step# | |||||||
| ≥1 step improvement | 4582 | 44% | 4225 | 41% | 1·15 | 1·09;1·22 | <0·0001 |
| ≥1 step worsening | 1449 | 14% | 1425 | 14% | 1·02 | 0·94;1·10 | 0·64 |
| Severe asthma exacerbations | 1001 | 10% | 1114 | 11% | 0·89 | 0·81;0·97 | 0·010 |
| Respiratory tract infection# | |||||||
| Pneumonia diagnosis | 147 | 1·4% | 204 | 2·0% | 0·72 | 0·58;0·89 | 0·0025 |
| Pneumonia with Rx antibiotic | 67 | 0·6% | 105 | 1·0% | 0·64 | 0·47;0·87 | 0·0045 |
| Hospitalisations# | 1792 | 17% | 1915 | 18% | 0·92 | 0·86;0·99 | 0·027 |
| Inpatient stay | 1091 | 11% | 1345 | 13% | 0·79 | 0·73;0·86 | <0·0001 |
| Outpatient stay | 911 | 9% | 851 | 8% | 1·08 | 0·98;1·19 | 0·14 |
| Ambulatory visits# | 10232 | 99% | 10096 | 97% | 2·01 | 1·64;2·47 | <0·0001 |
| Year 5 | AIT N=6545 | Control N=6545 | AIT vs· Control | ||||
| Asthma treatment step | |||||||
| ≥1 step improvement | 3391 | 52% | 3000 | 46% | 1·27 | 1·19;1·36 | <0·0001 |
| ≥1 step worsening | 918 | 14% | 947 | 14% | 0·96 | 0·87;1·06 | 0·48 |
| Severe asthma exacerbations | 571 | 9% | 724 | 11% | 0·77 | 0·69;0·86 | <0·0001 |
| Respiratory tract infection | |||||||
| Pneumonia diagnosis | 81 | 1·2% | 117 | 1·8% | 0·69 | 0·52;0·92 | 0·012 |
| Pneumonia with Rx antibiotic | 40 | 0·6% | 69 | 1·1% | 0·58 | 0·39;0·85 | 0·0068 |
| Hospitalisations | 1171 | 18% | 1256 | 19% | 0·92 | 0·84;1·00 | 0·059 |
| Inpatient stay | 739 | 11% | 867 | 13% | 0·83 | 0·75;0·93 | 0·0007 |
| Outpatient stay | 578 | 9% | 565 | 9% | 1·03 | 0·91;1·16 | 0·71 |
| Ambulatory visits | 6341 | 97% | 6343 | 97% | 0·99 | 0·81;1·21 | 0·96 |
| Year 9 | AIT N=571 | Control N=571 | AIT vs· Control | ||||
| Asthma treatment step | |||||||
| ≥1 step improvement | 320 | 56% | 283 | 50% | 1·30 | 1·03;1·64 | 0·032 |
| ≥1 step worsening | 79 | 14% | 108 | 19% | 0·69 | 0·50;0·94 | 0·025 |
| Severe asthma exacerbations | 41 | 7% | 60 | 11% | 0·66 | 0·44;1·00 | 0·060 |
| Respiratory tract infection | |||||||
| Pneumonia diagnosis | 9 | 1·6% | 12 | 2·1% | 0·75 | 0·31;1·78 | 0·66 |
| Pneumonia with Rx antibiotic | 4 | 0·7% | 9 | 1·6% | 0·44 | 0·14;1·44 | 0·26 |
| Hospitalisations | 93 | 16% | 121 | 21% | 0·72 | 0·54;0·98 | 0·040 |
| Inpatient stay | 61 | 11% | 88 | 15% | 0·66 | 0·46;0·93 | 0·022 |
| Outpatient stay | 42 | 7% | 49 | 9% | 0·85 | 0·55;1·30 | 0·51 |
| Ambulatory visits | 546 | 96% | 549 | 96% | 0·88 | 0·49;1·57 | 0·77 |
Categorical variables are reported as n % and changes as odds ratio (OR) and 95% confidence interval (CI) from pre-index year; P-values are between group comparison of AIT vs. control subjects; Asthma treatment step [change]: The definition of improvement or worsening in asthma treatment step was met, if subjects with pre-existing asthma changed asthma treatment step compared to the pre-index year. The asthma treatment steps were pre-defined categories based on asthma diagnoses codes and asthma medication prescriptions during pre-index and post-index years. Treatment step 1: Asthma diagnosis in the absence of controller asthma medication; Treatment step 2: Monotherapy with either low dose ICS or LTRA; Treatment step 3: Dual therapy or therapy with medium-high ICS, LABA or methylxanthine; Treatment step 4: Triple therapy or therapy with anti-IgE or anti-IL-5; Severe asthma exacerbation: 3-point composite of either new systemic corticosteroid prescription, status asthmaticus recorded in ambulatory care or hospitalisation for asthma. Only selected years are presented: Year 3 = expected end of treatment; Year 5 = duration of long-term RCTs investigating disease-modification, Year 9 = last year of observation.Rx: prescriptions; AIT: allergen immunotherapy; ICS: inhaled corticosteroids; LABA: long-acting beta2-agonists; LTRA: leukotriene receptor antagonists; IL: interleukin