Engineering study comparing injection force and dose accuracy between two prefilled insulin injection pens.

OBJECTIVE: This study compared injection force (measured by glide force [GF] and glide force variability [GFV]) and dosing accuracy of the Humalog KwikPen * (prefilled insulin lispro [Humalog dagger] pen, Eli Lilly and Company, Indianapolis, IN) and the Next Generation FlexPen double dagger (prefilled insulin aspart [NovoRapid section sign] pen, Novo Nordisk A/S, Bagsvaerd, Denmark). * Humalog KwikPen is a registered trademark of Eli Lilly and Company, Indianapolis, IN, USA. dagger Humalog is a registered trademark of Eli Lilly and Company, Indianapolis, IN, USA. double dagger FlexPen is a registered trademark of Novo Nordisk A/S, Bagsvaerd, Denmark. section sign NovoRapid is a registered trademark of Novo Nordisk A/S, Bagsvaerd, Denmark. RESEARCH DESIGN AND METHODS: A total of 100 prefilled insulin pens (50 insulin lispro pens, 50 insulin aspart pens) were tested using two dose sizes (30 U and 60 U). In all, 50 devices (25 of each type) were tested at 10 U/s dosing speed and 50 were tested at 6.6 U/s. Devices were used per manufacturer instructions. Dose accuracy (represented as absolute dose error %), maximum and average GF, and GFV data were automatically collected by the test system for all datasets (dose size/dosing speed/device type). The test system controlled for potential dosing errors. RESULTS: The insulin lispro pen demonstrated a significantly lower median maximum GF at both dosing speeds: (2.83 vs. 3.92 lbs [30 U] and 3.00 vs. 4.14 lbs [60 U]) at 10 U/s; (1.85 vs. 2.93 lbs [30 U] and 2.14 vs. 3.02 lbs [60 U]) at 6.6 U/s, all p < 0.0001. For all datasets, the median GFV was significantly lower for the insulin lispro pen, p < 0.0001. Median dose error was comparable between device types when tested at 10 U/s dosing speed; however, at 6.6 U/s, the median dose error was significantly lower for insulin lispro pen compared to insulin aspart pen (0.47 vs. 0.67% [30 U] and 0.50 vs. 0.78% [60 U], both p < 0.05). CONCLUSIONS: The insulin lispro pen had significantly lower median GF and GFV compared with insulin aspart pen when tested at two dose sizes and two dosing speeds. Median dose error was similar between the device types at the 10 U/s dosing speed, but median dose error was significantly lower for the insulin lispro pen at the 6.6 U/s dosing speed. A limitation of this study was that it was executed as an open label study.

Assessment of patient-reported outcomes of insulin pen devices versus conventional vial and syringe.

Patient-reported outcomes (PROs) associated with insulin therapy are potentially important determinants of adherence to diabetes management programs. This article reviews published evidence of PROs over the past 3 decades in patients with type 1 diabetes (T1D) and/or type 2 diabetes (T2D) who used vial and syringe for insulin delivery compared to those who used insulin pens. Based on predetermined selection criteria, articles were identified through a search of primary sources published from January 1980 to February 2008. Two independent reviewers determined study eligibility and performed a detailed evaluation of the articles that met the selection criteria. Of the 124 articles screened, 41 met selection criteria. Approximately 75% of the selected articles were published between 1990 and 2008, and a majority (78%) of the research studies was conducted outside the United States. Most (>75%) of the studies evaluated male and female patients with T1D and/or T2D and mean ages around 45 years. Studies used varied comparative study designs with follow-up periods ranging from 2 weeks to 5 years. The PROs assessed in these articles included preference, acceptability, treatment satisfaction, ease of use, convenience, injection pain, handling, and dosing. Most articles (n = 36) showed more favorable PROs for insulin pen users compared to vial and syringe users. These findings have potential clinical and policy implications for patients, diabetes care providers, and/or payers to make evidence-based decisions regarding ways to facilitate initiation and management of insulin therapy.

Effect of exenatide on 24-hour blood glucose profile compared with placebo in patients with type 2 diabetes: a randomized, double-blind, two-arm, parallel-group, placebo-controlled, 2-week study.

OBJECTIVE: The aim of this study was to examine the glucose-lowering effect of exenatide over 24 hours in patients with type 2 diabetes with inadequate glycemic control using metformin, with or without a thiazolidinedione (TZD). METHODS: This randomized, double-blind, 2-arm, parallel-group, placebo-controlled, 2-week study was conducted in patients with type 2 diabetes with inadequate glycemic control, despite metformin with or without a TZD. Patients underwent a baseline and a week-2 (study end) 24-hour admission during which serial serum glucose measurements were taken. Preprandial and postprandial concentrations of triglycerides and free fatty acids were also measured. Meals provided for each patient were identical at the baseline and week-2 assessments. Following the baseline admission, patients were randomized to receive SC injections of either exenatide (5 microg BID for 1 week, then 10 microg BID for the next week) or placebo (volume equivalent) for 14 days. RESULTS: A total of 30 patients (19 women [63%], 11 men [37%]; mean [SD] age, 52.6 [11.2] years; weight, 94.3 [23.0] kg; body mass index, 34.2 [6.1] kg/m(2); glycosylated hemoglobin value, 8.0% [0.9%]; diabetes duration, 8.7 [5.6] years; race, Hispanic 18 [60%], white 10 [33%], black 2 [7%]) were eligible. Seventeen patients (57%) were randomized to treatment with exenatide and 13 patients (43%) received placebo. Concurrent antidiabetic medications were metformin only (n = 19 [63%]) and metformin plus a TZD (n = 11 [37%]). All postbaseline values were least squares mean (SE). After 2 weeks (study end), the 24-hour time-average glucose values were 7.0 (0.2) and 8.8 (0.3) mmol/L for exenatide-treated and placebo-administered patients, respectively (P < 0.001). The glucose values for patients treated with exenatide were lower compared with those in patients who received placebo 2 hours after the morning meal (6.6 [0.4] vs 12.0 [0.5] mmol/L; P < 0.001), the midday meal (8.8 [0.5] vs 11.8 [0.6] mmol/L; P = 0.001), and the evening meal (6.8 [0.4] vs 11.3 [0.4] mmol/L; P < 0.001). The mean durations of patient exposure to glucose concentrations >7.8 and >11.1 mmol/L were significantly shorter for the exenatide group compared with the placebo group (>7.8 mmol/L: 6.8 [0.9] vs 14.1 [1.1] hours; >11.1 mmol/L: 1.0 [0.7] vs 4.7 [0.8] hours; both, P < 0.001). After 2 weeks, the postprandial triglyceride excursions after the morning and evening meals for patients treated with exenatide were significantly lower compared with those treated with placebo. There was no apparent effect on free fatty acid concentrations. CONCLUSIONS: In these patients with type 2 diabetes, exenatide was associated with significantly reduced glucose concentrations at multiple time points during 24 hours, with the greatest effect seen on postprandial glucose concentrations. In addition, exenatide was associated with decreased overall hyperglycemic exposure and significantly decreased postprandial triglyceride excursions. These results are consistent with those seen in other studies that reported the effectiveness of exenatide in controlling hyperglycemia in patients with type 2 diabetes.

Preference for insulin delivery systems among current insulin users and nonusers.

BACKGROUND: It is not known whether preferences for the vial and syringe (VS) or the insulin injection pen device (IIPD) differ between current insulin users and nonusers. Additional benefits in treatment might be realized if preference were considered when discussing insulin use with patients initiating or changing insulin treatment. OBJECTIVE: The objective of this study was to examine respondent preferences for the VS and the IIPD between current insulin users and nonusers. METHODS: US residents with type 1 or 2 diabetes mellitus who responded to a year-2001 mail survey completed a 19-item self-administered questionnaire designed to assess respondents' expectations of attributes related to the VS and IIPD. Items were analyzed on a 5-point Likert-type scale with higher scores indicating greater agreement that attributes met expectations. Composite scores for ease of use, activity interference, and social acceptability were used to further examine differences between insulin users and nonusers regarding their preferences for the VS or IIPD. Observed differences in preferences were evaluated statistically using the chi-square test, paired Student t test, and regression analysis. RESULTS: Questionnaires were received from 302 respondents, producing an adjusted response rate of 20.8%. Respondents ranged in age from 18 to 83 years (mean [SD], 52.4 [13.2] years), with 62% reporting annual income above 25,000 US dollars. Of the 242 usable responses, 99 respondents were insulin users and 143 were not. Statistical evaluation using analysis of variance revealed significant regression coefficients (P < or = 0.001) for both insulin users and nonusers for each of the 3 dimensions (ease of use, activity interference, and social acceptability with respect to preference). CONCLUSIONS: Based on this survey analysis, overall preference for the IIPD appeared to be higher compared with the VS among both insulin users and nonusers. Social acceptability was the strongest predictor of preference for the IIPD. For current insulin users, social acceptability and ease of use were significant predictors of preference for the VS. For insulin nonusers, these results suggested that patient discussions about VS should emphasize activity interference and ease of use.

Development of an instrument to assess expectations of and preference for an insulin injection pen compared with the vial and syringe.

BACKGROUND: Before using a product, patients form expectations regarding the extent of a product's desirable attributes. These expectations can be used to understand their preference and anticipate potential satisfaction with the product. OBJECTIVE: The aim of this study was to produce a valid and reliable data collection instrument (the Insulin Injection Preference questionnaire [IIP-q]) to measure expectations of and preference for the insulin injection pen compared with the vial and syringe. METHODS: This study was initiated at the University of Mississippi (University, Mississippi). The IIP-q was developed to determine the extent to which respondents' prepurchase expectations of a product's attributes relate to preference for an insulin injection pen compared with the vial and syringe. Instrument development began with item generation related to product attributes important to patients who inject insulin. Items originated from an extensive search of the peer-reviewed Internet-based literature, marketing reports, clinical studies, and existing instruments. Content validity also was assessed using expert panel and focus group review. The resultant instrument (the IIP-q) was mailed to 1200 patients known to have type 1 or type 2 diabetes mellitus who either did or did not use insulin. Subscales were identified through exploratory factor analysis. Reliability and validity were assessed using Cronbach alpha for subscale items. Product-moment correlations between subscale dimensions and 2 global measures of preference were used to test the relationship between attribute expectations and preference. RESULTS: Seventeen of the questionnaires were returned as undeliverable, leaving 1183 in the sample population. Questionnaires were received from 302 individuals, 55 of whom failed to complete > or = 85% of the items and thus were not included in the final analysis. Of the 247 respondents (135 women, 112 men; mean [SD] age, 52.4 [13.2] years (range, 18-83 years]), 99 (40.1%) were current insulin users and 143 (57.9%) were not using insulin. Exploratory factor analysis resulted in a 13-item solution (Cronbach alpha = 0.92), accounting for 73.6% of the total explained variance. Ease of use, activity interference, and social acceptability emerged as expectation subscales from exploratory factor analysis. Cronbach alpha for items comprising the subscales ranged from 0.82 to 0.92. The 3 subscales were significantly correlated with patient preference (ease of use, r = 0.520, P < 0.001; activity interference, r = 0.570, p < 0.001; social acceptability, r = 0.602, p < 0.001). CONCLUSIONS: The results of the present study provide support for the IIP-q as a reliable and valid instrument to assess patient expectations of product attributes and preference. This instrument can be modified for use in clinical trials to determine the role of patient expectations and preference in their judgments regarding satisfaction with insulin delivery devices.