Quality of diabetes care in cancer: a systematic review.

Purpose: Overlooking other conditions during cancer could undermine gains associated with early detection and improved cancer treatment. We conducted a systematic review on the quality of diabetes care in cancer.

Data sources: Systematic searches of Medline and Embase, from 1996 to present, were conducted to identify studies on the quality of diabetes care in patients diagnosed with cancer.

Study selection: Studies were selected if they met the following criteria: longitudinal or cross-sectional observational study; population consisted of diabetes patients; exposure consisted of cancer of any type and outcomes consisted of diabetes quality of care indicators, including healthcare visits, monitoring and testing, control of biologic parameters, or use of diabetes and other related medications.

Data extraction: Structured data collection forms were developed to extract information on the study design and four types of quality indicators: physician visits, exams or diabetes education (collectively 'healthcare visits'); monitoring and testing; control of biologic parameters; and medication use and adherence.

Results of data synthesis: There were 15 studies from five countries. There was no consistent evidence that cancer was associated with fewer healthcare visits, lower monitoring and testing of biologic parameters or poorer control of biologic parameters, including glucose. However, the weight of the evidence suggests cancer was associated with lower adherence to diabetes medications and other medications, such as anti-hypertensives and cholesterol-lowering agents.

Conclusion: Evidence indicates cancer is associated with poorer adherence to diabetes and other medications. Further primary research could clarify cancer's impact on other diabetes quality indicators.