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Medication Adherence and its Effect on Diabetes Outcomes 

Feb 29, 2020
Editor: David L. Joffe, BSPharm, CDE, FACA

Author: Jordan Boyd, PharmD. Candidate Florida Agricultural & Mechanical University School of Pharmacy

Is there a benefit to keeping it “simple” when determining appropriate regimens for patients with diabetes? Study looks at SIMPLE (simple basal insulin titration, Metformin plus liraglutide for type 2 diabetes with very elevated HbA1c) regimen.  

It is essential to any disease state for clinicians to emphasize proper medication adherence to prescribed medication regimens, to facilitate the best possible clinical outcomes. In type 2 diabetes, this emphasis on medication adherence is even more critical as patients’ long-term prognoses can often be affected by actions taken in the early stages of diagnosis and treatment. A patient’s adherence to their regimen is directly linked to their level of glycemic control. Currently, adherence in adult type 2 diabetes patients is low, and this is often due in part to the complexity of the prescribed regimens. Yes, guidelines do call for multiple oral agents and usually multiple insulin injections a day, but is there a way to simplify these regimens to facilitate improved adherence and in turn, better outcomes for patients?  

SIMPLE (simple basal insulin titration, Metformin plus liraglutide for type 2 diabetes with very elevated HbA1c) compared regimens with GLP1RA+ BI (glucagon-like peptide 1 receptor antagonist + basal insulin) to a BBI (basal-bolus insulin) regimen in adult type 2 diabetes patients.  

The objective of the study was to observe medication adherence to a GLP1RA+BI compared with a BBI regimen and determine the effect each respective regimen had on both patients’ reported and clinical outcomes. The baseline predictors of adherence were also evaluated. All study participants were 18 years or older and had type 2 diabetes with a confirmed A1c of greater than 10%. Patients were either placed on a GLP1RA+ BI regimen or a BBI regimen. Patients in the BI group were started on insulin detemir and self-titrated their daily dose according to a prespecified sliding scale which targeted a fasting blood glucose of between 71 and 100 mg/dL. Those patients in the GLP1RA group were started on liraglutide 1.8mg daily and titrated up to their maximum tolerated dose. Those patients in the BBI group were started on insulin aspart before their main meals. These patients also self-titrated according to a specific protocol. Metformin at the highest tolerated dose was either continued or started in all patients who had no contraindications. All injectable medications were provided in the pen form which they were to bring to each visit during the follow-up portion of the study. Follow-up was conducted at 1, 3, and 6 months after patients were randomized. At each follow-up visit, an adherence rate was calculated by dividing the amount of each product used by the expected amount of product to be used over the number of days between each visit. Patients were classified as either >80% adherent or <80% adherent.  

At the final time of data collection, more patients in the GLP1RA + BI as compared with the BBI group had greater than 80% adherence to the insulin detemir (59.3% vs. 35.7%, p=0.02). The same was true of those patients randomized to receive liraglutide over insulin aspart (57.4% vs. 30.4%, p=0.007). The major baseline predictor of adherence was found to be age. Patients of advanced age had higher rates of adherence of 80% or higher (OR per 5-year increment=1.48, 95% CI 1.09 to 2.0, p=0.01). Patients with higher levels of adherence had more significant improvements in both weight and HbA1c. Patients randomized in the BBI group also had much higher rates of hypoglycemia. There were several limitations in the study, the first being the small sample size. Further studies would need to be done in larger groups as only about 150 patients were randomized in this trial. Secondly, adherence was only calculated when patients brought their study medication to the follow-up appointment; if they did not the participant was automatically classified as non-adherent.  

Based on the results of this study, it is clear that simpler regimens can facilitate patients being more adherent. Treatment with the GLP1RA + BI regimen compared with the BBI regimen had a greater quality of life, greater overall adherence, and more significant clinical improvements. There was also a decreased risk of hypoglycemia occurring when compared with the BBI group. Overall this study demonstrates that prescribing patients less complicated regimens yields more positive clinical benefits which in turn allows patients to live and lead healthier lives.   

Practice Pearls:  

  • As clinicians, it is essential to consider what effect a prescribed regimen will have on a patient’s day-to-day routine and quality of life. 
  • Simpler regimens have shown to lead to better patient adherence and, in turn, more positive clinical benefits when treating patients with diabetes. 
  • Working to improve medication adherence is the best strategy in slowing the progression of diabetes in patients who have already been diagnosed.


Patel S, Abreu M, Tumyan A, et al. Effect of medication adherence on clinical outcomes in type 2 diabetes: analysis of the SIMPLE study. BMJ Open Diab Res Care 2019;7:e000761. doi:10.1136/ bmjdrc-2019-000761 


Jordan Boyd, PharmD. Candidate of Florida Agricultural & Mechanical University School of Pharmacy  


See more about medication adherence in diabetes.