Table 1

Data source and methods

Data characteristics
Systematic reviews, n25
Systematic reviews including aged or comorbid outcomes, n22
Total number of studies included in systematic reviews842
 Studies with aged or comorbid outcomes, n96 (11.4%)
Total number of outcomes included in systematic reviews3187
 Aged or comorbid outcomes, n314 (9.9%)
Total number of infarct volume outcomes1866
 Aged or comorbid infarct volume outcomes, n163 (8.7%)
Publication date of included studies1956–2016
  • Data were drawn from the Collaborative Approach to Meta Analysis and Review of Animal Data from Experimental Studies (CAMARADES) Focal Ischaemic Stroke Database,45 a non-random sample of preclinical systematic reviews of interventions for ischaemic stroke. We analysed overall the frequency of modelling comorbidities in studies included in the database. We then assessed the impact of modelling advanced age or comorbidities on infarct volume outcomes. Normalised mean difference effect sizes, representing the percentage reduction in infarct volume after intervention (vs control), were combined using random effects meta-analysis with restricted maximum likelihood (REML) estimate of between-study variance. The impact of modelling advanced age or a comorbidity, the type of comorbidity and the type of intervention were assessed using univariate meta-regression.46