My primary research question of the systematic review is to understand the proportion of health service use for a specific condition. Majority of the included articles are retrospective studies using administrative or electronic records describing the proportion of health service use. There is no exposure or control. Risk of bias for cohort studies (JBI or new-castle Ottawa) have questions related to definition of case, exposure or outcomes. These are not appropriate for my included studies. What would be an appropriate risk of bias tool for this systematic review?