An Indirect Comparison of Changes in the Impact of Weight on Quality of Life Among Subjects with Type 2 Diabetes Treated with Antihyperglycemic Agents in Dual Therapy with Metformin.

INTRODUCTION: It is important to capture the patient experience with a diabetes treatment in clinical trials; however, use of instruments to assess patient-reported outcomes (PROs) in diabetes trials is inconsistent and results may not be reported alongside primary efficacy data. In lieu of head-to-head data, indirect comparisons can be used to compare competing interventions. In this study, we used indirect comparison methods to assess differences in PRO score changes between canagliflozin and other antihyperglycemic agents as add-on to metformin. METHODS: Literature searches were performed to identify studies that reported the same PRO instruments that were collected across four trials of canagliflozin in dual or triple therapy. Extensive searches identified only one study that was sufficiently similar in design and reported common PRO results using the Impact of Weight on Quality of Life-Lite (IWQoL-Lite): the DURATION-2 study of exenatide once-weekly (QW) versus sitagliptin and pioglitazone. This study was compared with the CANTATA-D study of canagliflozin versus sitagliptin. Bayesian indirect comparisons were performed to assess mean change in IWQoL-Lite total score. A fixed-effects model with noninformative priors was used to estimate between-treatment differences. Sensitivity analyses examined differences in trial populations. RESULTS: In the primary analysis, the probability that canagliflozin treatment results in greater improvement in IWQoL-Lite total score versus exenatide, sitagliptin, and pioglitazone was 60.0%, 89.9%, and 99.5%, respectively. When the CANTATA-D population was restricted using DURATION-2 inclusion/exclusion criteria, canagliflozin was also associated with a higher probability of having greater improvement in IWQoL-Lite than exenatide, sitagliptin, and pioglitazone. CONCLUSIONS: These findings suggest that improvements in the impact of weight on health-related quality of life may be greater with canagliflozin than exenatide, sitagliptin, and pioglitazone. This analysis also demonstrates the application of indirect comparison methodology to PRO data and provides examples of advantages and challenges associated with performing indirect comparisons of PRO data.

The Effect of Canagliflozin, a Sodium Glucose Cotransporter 2 Inhibitor, on Glycemic End Points Assessed by Continuous Glucose Monitoring and Patient-Reported Outcomes Among People With Type 1 Diabetes.

OBJECTIVE: To assess the effects of canagliflozin, a sodium glucose cotransporter 2 inhibitor, on glycemic parameters and measures of glucose variability assessed by a 9-point self-monitoring blood glucose (SMBG) and continuous glucose monitoring (CGM) profiles, and patient-reported outcomes as an add-on to insulin among participants with type 1 diabetes. RESEARCH DESIGN AND METHODS: In this randomized, double-blind study, 351 participants received canagliflozin 100 or 300 mg or placebo for 18 weeks. Change from baseline in daily mean glucose and SD was measured using a 9-point SMBG profile. In a subset of 89 participants who underwent CGM, the change from baseline in mean glucose, measures of glycemic variability (SD, coefficient of variation, and mean amplitude of glycemic excursions), and time spent in glycemic ranges were assessed. Change in treatment satisfaction was evaluated using the Diabetes Treatment Satisfaction Questionnaire (n = 328). RESULTS: At week 18, reductions in daily mean glucose and SD measured using the 9-point SMBG profile were seen with canagliflozin 100 and 300 mg versus placebo. Reductions in mean glucose (-1.2, -0.7, and 0.6 mmol/L) and measures of glycemic variability assessed by CGM, such as changes in glucose SD (-0.3, -0.7, and 0.1 mmol/L), were also seen with canagliflozin 100 and 300 mg versus placebo, respectively. Canagliflozin 100 and 300 mg were associated with increases in time spent within target (glucose >3.9 to ≤10.0 mmol/L) compared with placebo (11.6%, 10.1%, and -3.5%, respectively) and commensurate reductions in time spent above the target level (glucose >10.0 mmol/L; -12.7%,-7.6%, and 5.7%, respectively). Participants showed greater improvement in treatment satisfaction with canagliflozin versus placebo; reductions in insulin dose, SD of glucose, and body weight contributed to the relationship between canagliflozin and satisfaction change. CONCLUSIONS: Canagliflozin improved indices of glycemic variability and was associated with improvement in treatment satisfaction versus placebo over 18 weeks among participants with type 1 diabetes. Although these data from this study demonstrate the potential benefits of canagliflozin in people with type 1 diabetes, canagliflozin is not approved for the treatment of type 1 diabetes and should not currently be used in people with type 1 diabetes.

The Diabetes Intention, Attitude, and Behavior Questionnaire: evaluation of a brief questionnaire to measure physical activity, dietary control, maintenance of a healthy weight, and psychological antecedents.

BACKGROUND: This study assessed measurement properties of the 17-item Diabetes Intention, Attitude, and Behavior Questionnaire (DIAB-Q), which measures intention to engage in self-care behaviors, including following a diabetes diet and engaging in appropriate physical activity. METHODS: The DIAB-Q includes questions based on the Theory of Planned Behavior. Items were developed using published literature, input from health care professionals, and qualitative research findings in patients with and without type 2 diabetes mellitus (T2DM). In Stage I of the study, 23 adults with T2DM were interviewed to evaluate the content and clarity of the DIAB-Q. In Stage II 1,015 individuals with T2DM completed the DIAB-Q and supplemental questionnaires, including the Short Form-36 acute (SF-36), section III of the Multidimensional Diabetes Questionnaire, the Summary of Diabetes Self-Care Activities questionnaire, and self-administered items relevant to the treatment and management of T2DM (eg, blood pressure and glycated hemoglobin [HbA1c]) at baseline and 3-7 days later. Once the DIAB-Q scale structure was determined, its test-retest reliability, construct validity, and known-groups validity were evaluated, and minimal clinically important change was estimated. RESULTS: In Stage I, the 23 respondents surveyed generally reported that the DIAB-Q was clear and comprehensive and endorsed questions as relevant to their intentions to engage in diabetes-related self-care activities. Most subjects in Stage II were male, Caucasian, and married. Mean age was 63 years. Factor analysis revealed six psychological constructs (Behavior, Planning, Intention, Perceived Behavioral Control, Attitude, and Subjective Norm). Test-retest reliability was acceptable (≥0.70) for all scales, except Perceived Behavioral Control. Construct validity was demonstrated based on correlations with diabetes-specific items/scales and the SF-36. Known-groups validity was confirmed for Behavior, Planning, and Intention when respondents were categorized into groups that differed based on body mass index, disease severity, and HbA1c. Item scores were transformed to a 100-point scale, and minimal clinically important change estimates ranged from 6-11 points, representing the change that would be considered important to a respondent. CONCLUSION: The DIAB-Q is a brief, psychometrically sound, patient-reported outcome that can be used among individuals with T2DM to evaluate intention to engage in self-care behaviors.

Demystifying "patient-centered" care in type 2 diabetes: the role of systematic measurement.

Questionnaires are noninvasive, inexpensive measures that can identify key elements of the patient perspective that are important for the achievement of better outcomes in diabetes care.

The Importance of Weight Change Experiences for Performance of Diabetes Self-Care: A Patient-Centered Approach to Evaluating Clinical Outcomes in Type 2 Diabetes.

INTRODUCTION: The aim of this study was to examine the influence of weight change experiences over time on motivation to perform diabetes self-care behaviors using data from a study of canagliflozin (an agent that inhibits sodium glucose co-transporter 2) versus glimepiride in dual therapy with metformin and background diet/exercise. METHODS: Weight and motivation for performing healthy behaviors were collected at baseline and over time. The motivation questionnaire enabled categorization into two groups: those performing or not performing health behaviors. Four distinct patterns of weight change were determined: losing weight, gaining weight, and two patterns for fluctuating weight. The relationships between these patterns and motivation for weight loss, following a diet, and exercise were examined using logistic regression models. RESULTS: Of 1182 subjects, more than half were already performing behaviors to lose weight, diet, and exercise at baseline. Among those who were not, 52% (246/474) started taking action to lose weight after baseline, 54% (241/448) started following a diet, and 42% (232/556) started exercising. Weight change patterns were significantly related to performance of healthy behaviors at follow-up (week 36). Compared to the weight gain pattern, those who experienced a continuous weight loss pattern from baseline to week 36 were 2.2 (95% confidence interval 1.49, 3.37) times more likely to perform the healthy behaviors. Baseline behavior and confidence were also predictive of performing healthy behaviors. CONCLUSION: The current work highlights the importance of weight change patterns for performance of diabetes self-care. Tracking weight patterns over time, assessing confidence for performance of healthy behaviors, and being aware of the relationship between weight changes and diabetes self-care behaviors are viable, concrete ways to practice patient-centered care. FUNDING: Janssen Global Services, LLC.

Pragmatic measurement of health satisfaction in people with type 2 diabetes mellitus using the Current Health Satisfaction Questionnaire.

BACKGROUND: The concept of diabetes-related health satisfaction encompasses issues specifically related to living with diabetes (eg, blood glucose, blood pressure levels, body weight). Health satisfaction is more specific than overall health-related quality of life because it considers disease-related factors, and is different from diabetes treatment satisfaction because it addresses issues not specifically related to treatment. Low levels of health satisfaction in people with type 2 diabetes mellitus (T2DM) may negatively affect self-care behaviors and treatment outcomes; however, there are currently no instruments available to assess health satisfaction in this population. This study assessed the measurement properties of a newly constructed, 14-item Current Health Satisfaction Questionnaire (CHES-Q) designed to assess diabetes-related health satisfaction and knowledge of the disease and important laboratory results. METHODS: In-depth interviews were conducted in 23 adults with T2DM to confirm the content and clarity of the CHES-Q. The revised instrument was administered to 1,015 individuals with T2DM, along with supplemental questionnaires, including the Short Form-36. All subjects completed the questionnaires again 3 to 7 days later. CHES-Q test-retest reliability, construct validity, and known-groups validity were evaluated. RESULTS: In general, respondents found the CHES-Q to be clear and comprehensive. Test-retest reliability was generally acceptable for all items (≥0.70), except for three that fell just below the widely accepted cut-point of 0.70 (range 0.63-0.69). Convergent and divergent validity was demonstrated based on hypothesized correlations with the Short Form-36. Known-groups validity was confirmed for most CHES-Q items when respondents were split into groups known to differ clinically by body mass index, disease severity, or glycated hemoglobin. CONCLUSION: Health satisfaction is a unique and important concept to consider when developing individualized strategies for managing T2DM because health satisfaction is a key element of patient-centered care. The CHES-Q allows for the pragmatic assessment of many aspects of diabetes-related health satisfaction in a single questionnaire.

The complexity of care for patients with rheumatoid arthritis: metrics for better understanding chronic disease care.

BACKGROUND: Patients with rheumatoid arthritis (RA) provide an important opportunity for understanding care of patients with a serious chronic condition. OBJECTIVES: We sought to characterize the complexity of care for patients with RA, including metrics describing the patient, the disease, and use of the health care system across time and place. METHODS: We undertook a prospective cohort study of 568 community-dwelling patients with RA by using observational data from clinically detailed telephone interviews at baseline and 2 years later in addition to medical record abstraction. Health status, comorbidity, use of disease-modifying antirheumatic drugs, visits, providers, provider types, encounter settings, and the discontinuity between patients and providers were studied. RESULTS: Within a 12-month window, 568 patients had 8686 outpatient encounters with the health care system with a mean of 3.41 unique providers per patient associated with a mean of 5 primary care and 6 rheumatologist visits. Half did not see a primary care physician, and 20% did not see a rheumatologist during 6-month periods despite their use of potentially toxic drugs, a mean of 4 comorbidities and progressive RA. Over the course of 24 months, 29% of patients changed their primary care provider, and 15% changed their rheumatologist. Patients were moderately impaired with mean SF-12 physical component score 37 (SD, 9). CONCLUSION: Patients with RA have frequent encounters with multiple providers and also frequent discontinuity of care. Recognizing the complexity of the care of patients with a chronic disease across multiple dimensions provides an opportunity to better understand challenges and opportunities in delivering high quality care.

Measuring process of arthritis care: the Arthritis Foundation's quality indicator set for rheumatoid arthritis.

OBJECTIVE: To describe the scientific evidence that supports each of the explicit process measures in the Arthritis Foundation's Quality Indicator Set for Rheumatoid Arthritis. METHODS: For each of the 27 measures in the Arthritis Foundation's Quality Indicator set, a comprehensive literature review was performed for evidence that linked the process of care defined in the indicator with relevant clinical outcomes and to summarize practice guidelines relevant to the indicators. RESULTS: Over 7500 titles were identified and reviewed. For each of the indicators the scientific evidence to support or refute the quality indicator was summarized. We found direct evidence that supported a process-outcome link for 15 of the indicators, an indirect link for 7 of the indicators, and no evidence to support or refute a link for 5. The processes of care described in the indicators for which no supporting/refuting data were found have been assumed to be so essential to care that clinical trails assessing their importance have not, and probably never will be, performed. The process of care described in all but 2 of the indicators is recommended in 1 or more practice guidelines. CONCLUSION: There are sufficient scientific evidence and expert consensus to support the Arthritis Foundation's Quality Indicator Set for Rheumatoid Arthritis, which defines a minimal standard of care that can be used to assess health care quality for patients with rheumatoid arthritis.

Effects of omega-3 fatty acids on cancer risk: a systematic review.

CONTEXT: Omega-3 fatty acids are purported to reduce the risk of cancer. Studies have reported mixed results. OBJECTIVE: To synthesize published and unpublished evidence to determine estimates of the effect of omega-3 fatty acids on cancer risk in prospective cohort studies. DATA SOURCES: Articles published from 1966 to October 2005 identified through MEDLINE, PREMEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and CAB Health; unpublished literature sought through letters to experts in the neutraceutical industry. STUDY SELECTION: A total of 38 articles with a description of effects of consumption of omega-3 fatty acids on tumor incidence, prospective cohort study design, human study population; and description of effect of omega-3 among groups with different levels of exposure in the cohort were included. Two reviewers independently reviewed articles using structured abstraction forms; disagreements were resolved by consensus. DATA EXTRACTION: Two reviewers independently abstracted detailed data about the incidence of cancer, the type of cancer, the number and characteristics of the patients, details on the exposure to omega-3 fatty acids, and the elapsed time between the intervention and outcome measurements. Data about the methodological quality of the study were also abstracted. DATA SYNTHESIS: Across 20 cohorts from 7 countries for 11 different types of cancer and using up to 6 different ways to categorize omega-3 fatty acid consumption, 65 estimates of the association between omega-3 fatty acid consumption were reported. Among these, only 8 were statistically significant. The high degree of heterogeneity across these studies precluded pooling of data. For breast cancer 1 significant estimate was for increased risk (incidence risk ratio [IRR], 1.47; 95% confidence interval [CI], 1.10-1.98) and 3 were for decreased risk (RR, 0.68-0.72); 7 other estimates did not show a significant association. For colorectal cancer, there was 1 estimate of decreased risk (RR, 0.49; 95% CI, 0.27-0.89) and 17 estimates without association. For lung cancer one of the significant associations was for increased cancer risk (IRR, 3.0; 95% CI, 1.2-7.3), the other was for decreased risk (RR, 0.32; 95% CI, 0.13-0.76), and 4 other estimates were not significant. For prostate cancer, there was 1 estimate of decreased risk (RR, 0.43; 95% CI, 0.22-0.83) and 1 of increased risk (RR, 1.98; 95% CI, 1.34-2.93) for advanced prostate cancer; 15 other estimates did not show a significant association. The study that assessed skin cancer found an increased risk (RR, 1.13; 95% CI, 1.01-1.27). No significant associations between omega-3 fatty acid consumption and cancer incidence were found for aerodigestive cancer, bladder cancer, lymphoma, ovarian cancer, pancreatic cancer, or stomach cancer. CONCLUSIONS: A large body of literature spanning numerous cohorts from many countries and with different demographic characteristics does not provide evidence to suggest a significant association between omega-3 fatty acids and cancer incidence. Dietary supplementation with omega-3 fatty acids is unlikely to prevent cancer.

Telephone reminder calls increased response rates to mailed study consent forms.

BACKGROUND: This study assessed the impact of follow-up reminder phone calls on response rates to a mailed consent form packet. METHODS: Patients with rheumatoid arthritis were invited to enroll in a study by signing and returning consent forms by mail. Patients not returning completed study consent forms were called and reminded to return the signed consent forms. RESULTS: Among 724 mailed consent form packets, 376 (52%) were returned without further follow-up. Follow-up reminder calls were made to 220 of the 348 patients who did not return signed consent forms. Among subjects contacted by phone, 67 (31% of those called) returned signed consent forms. CONCLUSION: Follow-up reminder phone calls raised the overall consent rate of 52 to 61%, suggesting that they can be an effective technique in increasing response rates.