Ferrans and Powers Quality of Life Index (QLI) The QLI was developed by Carol Estwing Ferrans and Marjorie Powers in 1984 to measure quality of life in terms of satisfaction with life. Only the symptoms subscale is a proxy measure of the parent’s HRQOL. Materials and Methods: This case-control study was done among type 2 diabetes mellitus patients attending Medicine Outpatient department of a 780-bedded rural medical college located in central India. Self-managing the multiple daily demands of this chronic disease while negotiating the developmental tasks of young adulthood is neither well described nor understood. Medical data were extracted from medical records at community health centres. The patients reported “some or extreme problems” most frequently in Pain/Discomfort (69.3%) and Anxiety/Depression (56.6%) dimensions of EQ-5D. The discriminant validity of the questionnaire was tested using ‘t’ test for metabolic control, co-morbidities, insulin use and gender.
Test-retest ICC coefficients for the generic HrQoL module were 0.913 for the children and 0.820 for the parent version. Patients were primarily white (75.5%), female (55.9%), middle aged (52.4% were aged ≥60 years), and of modest socioeconomic status (49.5% with income under $35,000 and 50.3% with no college). Interestingly, in the analysed set of variables, education played no independent role with respect to HRQOL. Similar results were found in another study where diabetes had the largest impact on “enjoyment of food” and the least impact on “others fussing” . Respondents were divided into five prior treatment subgroups: 1) a group that had never used insulin; 2) a group that had never used mixed insulin; 3) a group that had used 70/30 mixed insulin, but not a pen; 4) a group that had used 70/30 mixed insulin in a pen; and 5) a group that had used various mixed insulins via pen or syringe and did not fit into one of the other groups. Thus, each group allowed a comparison of the study pen with a different treatment strategy. Respondents rated the study pen significantly more positively than their prior treatment on all measures in the total sample and in all subgroups (Table 1).
The advantage for the study pen ranged from 0.5 to 3.7 SD units (median 1.4). Key determinants of overall treatment preference were identified by hierarchical multiple regression analyses controlling for age, sex, race/ethnicity, and education. Perceived convenience, flexibility, clinical efficacy, and quality of life were entered into the models together (results not shown). In the total sample, all ratings of the study pen except quality of life had significant independent associations with overall preference. A national design for the prevention and control of diabetes. Patients overwhelmingly preferred the study pen to their prior treatment strategies, and using the study pen was associated with enhanced convenience, flexibility, perceived clinical efficacy, and quality of life for all subgroups of patients. These advantages were all >0.5 SD units (corresponding to a “moderate” effect size ), which was identified in a recent review of patient-reported outcomes (10) as the criterion for the minimum difference that a person would be able to detect.
So the differences observed in this study were meaningful as well as statistically significant. Finally, some studies looking at the relationship between duration of DM and HRQoL have shown that a longer duration of the disease was related to lower HRQoL;20,22,23,32,36 however, others7,12,16,26,33 found no relationship between diabetes duration and HRQoL, and one43 found that an increased duration of DM was related to better HRQoL. We found differences of the sort one might expect. Patients previously naïve to insulin tended to report the greatest improvements in clinical efficacy and the smallest benefits in convenience and flexibility. Among patients who had used insulin previously, those who had only used syringes to deliver unmixed insulin reported the greatest benefits on all outcomes. As patients’ prior treatment strategy more closely approximated the study intervention (from pen naïve with unmixed insulin, to pen naïve with mixed insulin, to pen experienced with mixed insulin) there was a decrease in the advantage of the study system in convenience, flexibility, perceived clinical efficacy, and quality of life. Our study is the first to systematically assess factors contributing to patients’ reported preference for pen devices over syringes (1–6).
Our results indicated that convenience, flexibility, perceived clinical efficacy, and quality of life each made independent contributions to preference for treatment strategies among selected patient subgroups, and the contributing factors differed for different subgroups. The major limitation of this study is the result of various sources of sampling bias. Therefore, it is prudent to assume that the results are most likely to be representative of patients willing to change to an insulin pen, including those not satisfied with their current form of treatment. Neither knew the treatment they had been randomized to receive; 54 individuals were thus randomized and treated. When patients reported more than one prior treatment, we assumed that the most intensive treatment was the most recent one, which could have led to underestimating the perceived advantages of the study pen. Such multi-attribute utility models include the EuroQol (EQ-5D), the Health Utilities Index (HUI) and the Quality of Well Being index (QWB). Patients new to insulin in this study reported improved quality of life and better glucose control and said their treatment had become more convenient and flexible, suggesting that pen use could counter some of the common reasons that patients raise for resisting insulin therapy (11–12).
For patients already using insulin, an insulin delivery system that improves treatment satisfaction could help facilitate intensified treatment and result in improved clinical outcomes (13). In summary, we have highlighted important determinants of quality of life in patients with diabetes and provided evidence to suggest that diabetes quality of life may be enhanced when care is provided by GPs in a primary care setting. Preparation of this research report was funded by an unrestricted educational grant from Novo Nordisk Pharmaceuticals (NNPI). NNPI funded data collection and donated the medication and delivery devices. Quintiles designed and implemented the study under contract from NNPI. Quintiles provided the authors with the data and a description of the data collection methods. R.R.R.
has served on advisory panels for Novo Nordisk Pharmaceuticals; has received honoraria from Novo Nordisk (DK), Novo Nordisk Pharmaceuticals, and Takeda Pharmaceuticals; has received consulting fees from Amylin Pharmaceuticals, MannKind Biopharmaceuticals, Medtronic MiniMed, Novo Nordisk (DK), Novo Nordisk Pharmaceuticals, and Takeda Pharmaceuticals; and has received research/grant support from Medtronic MiniMed, Novo Nordisk (DK), and Novo Nordisk Pharmaceuticals.