Does type of bolus insulin matter in the hospital? Retrospective cohort analysis of outcomes between patients receiving analogue versus human insulin.

Background: Poor glycemic control in hospitalized patients has been associated with increased morbidity and mortality. Research suggests that analogue bolus insulin may be more effective in achieving blood glucose (BG) control compared with human bolus insulin.

Objective: This study compares mortality, length of stay (LOS), costs, and BG control in hospitalized patients receiving either analogue or human bolus insulin.

Methods: This retrospective cohort analysis used data from January 1, 2004, to December 31, 2007, within the Health Facts database (Cerner Corporation, Kansas City, Missouri). Nonsurgical adult patients who received exclusively analogue or human bolus insulin during hospitalization were included in the study. Propensity score matching and multivariate regression analyses were used to compare patients treated with analogue versus human bolus insulin. The study outcomes were in-hospital mortality, hospital LOS among survivors (to avoid potentially short hospitalizations among nonsurvivors distorting results), and hospitalized BG control (present vs absent), defined as having a mean BG of 70 to <200 mg/dL during hospitalization.

Results: In total, 35,049 participants met the inclusion criteria and 5568 of 7754 patients in the analogue group were matched by their propensity scores to patients in the human bolus group (mean age, 67.1 years; 53% women; 77% white). On propensity score analysis, analogue bolus insulin was associated with lower mortality (relative risk [RR] = 0.52; 95% CI, 0.45-0.61) and shorter LOS (0.668-day reduction; 95% CI, 0.44-0.89) compared with human bolus insulin. However, analogue insulin was associated with only a modest benefit for BG control (RR = 0.88; 95% CI, 0.81-0.95). The multivariate regression analysis produced similar findings.

Conclusions: In this cohort of hospitalized patients, analogue bolus insulin was associated with lower mortality, shorter LOS, and modestly better BG control compared with patients treated with human bolus insulin. These results highlight the need for a randomized controlled clinical trial comparing outcomes by bolus insulin type in the hospital setting to determine a true mortality benefit.