Quality assessment of the studies included in the meta-analysis to assess the risk of stroke associated with SLE
| First author and year of publication | Source of SLE population | Ascertainment of SLE | Incident or prevalent SLE at start of follow-up | Exclusion of prevalent stroke at start of follow-up | Matching | Confounders considered and adjusted for | Newcastle-Ottawa Quality Assessment Scale |
|---|---|---|---|---|---|---|---|
| Agha, 201413 | Population based | ≥2 ICD codes in a non-rheumatology unit or ≥1 ICD code in rheumatology | Incident (5-year washout) | Yes | Birth year, sex, calendar year | Number of hospitalisations, comorbidity, medications | 9 |
| Bengtsson, 20129 | Population based | Clinical cases, physician diagnosis, ACR criteria ≥4 | Prevalent | No | Age, sex | Sex, year | 8 |
| Chang, 201314 | Population based | ICD code, registered for catastrophic illness | Incident (5-year washout) | Yes | Age, sex | None | 7 |
| Chiu, 201215 | Population based | ICD code in rheumatology, registered for catastrophic illness | Incident (3-year washout) | Yes | Age, sex, comorbidities | Age, sex, comorbidity | 9 |
| Hak, 200916 | Cohort study | Initially self-reported via questionnaire with medical record review of all cases, ACR criteria ≥4 | Incident | Yes | None | Age, comorbidity, parental history of congestive heart disease, body mass index, physical exercise, smoking, alcohol, menopausal status, hormone use, medications, race | 9 |
| Liou, 201417 | Population based | ≥15 ICD codes in rheumatology | Unclear | Yes | Age, sex | Age, sex, comorbidity, urbanisation | 9 |
| Mok, 200918 | Hospital based | Clinical diagnosis, ACR criteria ≥4 | Unclear | No | None | Unclear | 4 |
| Ramagopalan, 201319 | Population based | Any ICD code in hospital day case care or inpatient admission | Incident and prevalent | Yes | None | Age, sex, time period, region, socioeconomic status | 9 |
| Wang, 201220 | Population based | ICD code from rheumatologist visits and registered for catastrophic illness | Incident (1-year washout) | Yes | Age, sex, index year (frequency matched) | Age, sex, urbanisation, income, comorbidity | 9 |
| Zöller, 201221 | Population based | Any ICD code in inpatient care | Incident and prevalent | Yes | None | Age, sex, period, socioeconomic status, region, comorbidity | 9 |
ACR, American College of Rheumatology; ICD, International Classification of Diseases; SLE, systemic lupus erythematosus.