Does splitting a tablet obtain the accurate dose?

Background: Physical manipulation of the manufactured dose form is a common practice, with almost a quarter of all drugs administered in primary care having their dose altered. Splitting a tablet can be advantageous as it facilitates swallowing, allows for dose flexibility and provides cost reductions. However, there are concerns these physical changes can lead to inaccurate portions resulting in significant variations from the prescribed dose. Thus, the review described in this protocol aims to summarise the literature assessing the effect of tablet splitting on dose accuracy. Methods: Relevant studies will be identified through electronic searches in databases including EMBASE, MEDLINE, CINAHL, and the Cochrane Library, from the beginning of databases until January 2020. Studies investigating any drug, where the tablet was split, will be potentially eligible. Two reviewers will independently screen studies and extract data using standardised forms. Data extracted will include general study information, characteristics of the study, intervention characteristics and outcomes. Primary outcome is to assess dose accuracy of a split tablet measured by drug content or weight variability. Assessment of risk of bias will be dependent upon study design. If deemed feasible, meta-analysis will be performed. Results: The study described within this protocol will provide a synthesis of current evidence assessing the effect of tablet splitting on dose accuracy. Conclusion: The conclusion of our study will provide evidence to judge whether splitting a tablet results in an accurate half dose. Ethics and dissemination: Ethics approval was not required for this study. The results of the systematic review described will be published in a peer-reviewed journal. Registration details: PROSPERO CRD42018106252