Quality of Life of Patients with Type 1 Diabetes Mellitus Using Insulin Analog Glargine Compared with NPH Insulin: A Systematic Review and Policy Implications

Introduction Insulin analog glargine (GLA) has been available as one of the therapeutic options for patients with type 1 diabetes mellitus to enhance glycemic control. Studies have shown that a decrease in the frequency of hypoglycemic episodes improves the quality of life (QoL) of diabetic patients. However, there are appreciable acquisition cost differences between different insulins. Consequently, there is a need to assess their impact on QoL to provide future guidance to health authorities. Method A systematic review of multiple databases including Medline, LILACS, Cochrane, and EMBASE databases with several combinations of agreed terms involving randomized controlled trials and cohorts, as well as manual searches and gray literature, was undertaken. The primary outcome measure was a change in QoL. The quality of the studies and the risk of bias was also assessed. Results Eight studies were eventually included in the systematic review out of 634 publications. Eight different QoL instruments were used (two generic, two mixed, and four specific), in which the Diabetes Treatment Satisfaction Questionnaire (DTSQ) was the most used. The systematic review did not consistently show any significant difference overall in QoL scores, whether as part of subsets or combined into a single score, with the use of GLA versus neutral protamine Hagedorn (NPH) insulin. Only in patient satisfaction measured by DTSQ was a better result consistently seen with GLA versus NPH insulin, but not using the Well-being Inquiry for Diabetics (WED) scale. However, none of the cohort studies scored a maximum on the Newcastle-Ottawa scale for quality, and they generally were of moderate quality with bias in the studies. Conclusion There was no consistent difference in QoL or patient-reported outcomes when the findings from the eight studies were collated. In view of this, we believe the current price differential between GLA and NPH insulin in Brazil cannot be justified by these findings.