Table 1. Study endpoints and matching criteria.
| Study endpoints | |
| • Primary endpoint ○ Change in HbA1c from baseline to outcome period | |
| • Secondary endpoints ○ Increase in HbA1c* and/or the addition of antidiabetic medication from baseline to outcome period ○ Number of patients off the QOF target for HbA1c (HbA1c >7.5%) ○ Change in diabetes-related GP visits, hospitalisations, and glucose strip prescriptions† ○ Progression of ongoing diabetes treatment to insulin by time or dose | |
| Matching criteria | Categories |
| Sex | Male / female |
| Age (±5 years at index date‡) | NA |
| Smoking status at index date | Non-smoker / current smoker / ex-smoker |
| BMI at index date | Underweight / normal weight / overweight / obese |
| mMRC score[4] at index date | Missing / 0–1 / ≥2 |
| Exacerbations§ during baseline | 0–1 / ≥2 |
| FEV1, % predicted at index date | Missing / <50% / ≥50% |
| HbA1c¶ ±1 DCCT (%) during baseline | NA |
| Antidiabetic medication during baseline | None / non-insulin / insulin |
*Increase in HbA1c was defined as a change of ≥0.5% from baseline to outcome period. Antidiabetic medication during baseline was categorised as 1, 2 or ≥3 of non-insulin or insulin, and any progression from baseline to outcome within these categories was recorded as addition of an antidiabetic drug.
†GP visits: change in annual rate from baseline to outcome period; hospitalisations: increase from baseline to outcome period; glucose strip prescriptions: increase (>0.5 per year) from baseline to outcome period.
‡The index date was defined as the date of first ICS prescription or first/additional non-ICS prescription.
§Defined as the number of acute oral corticosteroid courses and antibiotic prescriptions for a lower respiratory tract infection.
¶Most recent value within 18 months prior to the index date.
BMI = body mass index; DCCT = Diabetes Control and Complications Trial units; FEV1 = forced expiratory volume in 1 second; GP = general practice; HbA1c = glycated haemoglobin; mMRC = modified Medical Research Council; NA = not applicable; QOF = Quality and Outcomes Framework.