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.