Adherence and persistence to a regimen of basal insulin in a pre-filled pen compared to vial/syringe in insulin-naïve patients with type 2 diabetes

Curr Med Res Opin. 2011 Sep;27(9):1709-17. doi: 10.1185/03007995.2011.598500. Epub 2011 Jul 11.


Objective: This study was conducted to compare adherence and persistence of patients initiating basal insulin therapy with Levemir FlexPen versus those initiating basal insulin therapy with NPH via vial and syringe.

Materials and methods: Data were gathered from a large US retrospective claims database, and included patients with type 2 diabetes that initiated basal insulin therapy with either Levemir FlexPen or NPH in vials. Patients were defined as adherent to therapy if they had a medication possession ratio (MPR) of ≥80% in the 12-month follow-up period and were defined as persistent with therapy if they had no gaps in insulin therapy in the follow-up period.

Results: After controlling for confounders using logistic regression, patients initiating therapy with Levemir FlexPen had 39% higher adjusted odds of achieving an MPR ≥80% versus patients initiating therapy with NPH vial (OR 1.39; 95% CI: 1.04-1.85). Analysis of persistence using a Cox proportional hazards model indicated that patients initiating Levemir FlexPen had a 38% lower hazard of discontinuation compared to NPH vial (HR 0.62, 95% CI: 0.55-0.70).

Limitations: Claims-based studies are limited to the extent that they accurately capture medical and pharmacy use. Also, relying on claims-based data limits the generalizability of the findings to similar populations and treatments.

Conclusions: These results suggest that persistence and adherence with insulin may be improved for patients initiating basal insulin therapy with Levemir FlexPen versus NPH vial.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Disposable Equipment*
  • Female
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / adverse effects
  • Insulin Detemir
  • Insulin, Isophane / administration & dosage
  • Insulin, Isophane / adverse effects
  • Insulin, Long-Acting / administration & dosage*
  • Insulin, Long-Acting / adverse effects
  • Male
  • Medication Adherence / statistics & numerical data*
  • Middle Aged
  • Pharmaceutical Preparations
  • Retrospective Studies
  • Syringes* / adverse effects


  • Hypoglycemic Agents
  • Insulin, Long-Acting
  • Pharmaceutical Preparations
  • Insulin Detemir
  • Insulin, Isophane