Mediators of medication adherence and glycaemic control and their implications for direct outpatient medical costs: a cross-sectional study

Diabet Med. 2018 Jun;35(6):807-815. doi: 10.1111/dme.13619. Epub 2018 Mar 30.

Abstract

Aims: To investigate the effects of diabetes-related distress and perception of hyperglycaemia on self-reported medication adherence and glycaemic control, as measured by HbA1c , and to compare the cost outcomes in patients with sub-optimally vs uncontrolled Type 2 diabetes mellitus.

Methods: We conducted a retrospective cross-sectional study that involved the review of a chronic disease database in Singapore. Data on clinical characteristics, diabetes-related distress, perception of hyperglycaemia, self-reported medication adherence and costs were obtained from the database. Mediation analyses were conducted using a linear regression-based approach. A final path model was built to illustrate the sequential mediating effects of diabetes-related distress and perception on the association of medication adherence and HbA1c concentration.

Results: Diabetes-related distress and perception of hyperglycaemia were significantly associated with medication adherence and HbA1c concentration. Mediation analyses showed a significant indirect effect of diabetes-related distress and perception of hyperglycaemia on medication adherence and HbA1c concentration. People with uncontrolled diabetes were found to incur significantly higher total direct medical costs than those with sub-optimally controlled diabetes (P = 0.034), with medication cost as the main cost driver (66.6%).

Conclusions: Identifying the influence of the sequential mediating effects of distress and perception was important in understanding the pathway between medication adherence and glycaemic control. This suggests the importance of a team-based approach to address these mediators and thus improve glycaemic control. Poor glycaemic control was also found to be associated with higher direct medical costs.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Body Mass Index
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / economics
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diabetes Mellitus, Type 2 / psychology
  • Female
  • Glycated Hemoglobin / metabolism
  • Health Expenditures
  • Health Knowledge, Attitudes, Practice
  • Humans
  • Hyperglycemia / economics
  • Hyperglycemia / prevention & control*
  • Hyperglycemia / psychology
  • Hypoglycemic Agents / economics
  • Hypoglycemic Agents / therapeutic use
  • Male
  • Medication Adherence / psychology*
  • Middle Aged
  • Perception
  • Retrospective Studies
  • Self Report
  • Singapore
  • Stress, Psychological

Substances

  • Glycated Hemoglobin A
  • Hypoglycemic Agents