PDB97 - Pen needle length and persistence among insulin pen users with type 2 diabetes mellitus

Abstract

To assess the impact of insulin pen needle (PN) length on persistence of prescribed insulin therapy among patients recently diagnosed with type 2 diabetes mellitus (T2DM). Patients 18 years and older diagnosed with T2DM who had at least one indexed claim from May 2009 through September 2010 were assessed from the Truven Health MarketScan Research Database. Inclusion required 1 year continuous enrollment pre and post-index insulin claim with ≤ 1 prescription for an oral anti-diabetic drug during the pre-index period. Patients diagnosed with T1DM or using specialty self-injectables during the pre-index period were excluded. Patients were grouped into three PN length cohorts: short (4 & 5mm), intermediate (6mm) and long (8 & 12.7mm) needle initiators. Persistence was evaluated at 6 and 12 months by the absence of 90 day gaps between insulin prescriptions. Differences in persistence between cohorts were compared for statistical significance using a Fisher’s exact test (95% CI, two-tail). The study included 21,622 patients with an average age of 59.1 years (SD=11.4). Most patients were within the long needle group (67.6%); followed by the short (21.5%) and intermediate (10.8%) needle users. The majority of patients were non-persistent at the end of the first year of insulin use, with only 38.4% being persistent. Within the first 6 months only 46.5% of patients were found to be persistent. However, of those patients who were persistent within first 6 months, the likelihood of them remaining persistent was high with 82.6% of users reporting no gaps at 1 year. When examining the correlation between needle length and persistence, short needle users were 4.9% (p<0.001) and 2.7% (p=0.001) more persistent at 6 months than intermediate and long needle users, respectively. Persistence rates were higher for those patients using shorter needles, particularly early on at earlier phases of insulin adoption.