Association of Real-time Continuous Glucose Monitoring With Glycemic Control and Acute Metabolic Events Among Patients With Insulin-Treated Diabetes.

Importance: Continuous glucose monitoring (CGM) is recommended for patients with type 1 diabetes; observational evidence for CGM in patients with insulin-treated type 2 diabetes is lacking. Objective: To estimate clinical outcomes of real-time CGM initiation. Design, Setting, and Participants: Exploratory retrospective cohort study of changes in outcomes associated with real-time CGM initiation, estimated using a difference-in-differences analysis. A total of 41 753 participants with insulin-treated diabetes (5673 type 1; 36 080 type 2) receiving care from a Northern California integrated health care delivery system (2014-2019), being treated with insulin, self-monitoring their blood glucose levels, and having no prior CGM use were included. Exposures: Initiation vs noninitiation of real-time CGM (reference group). Main Outcomes and Measures: Ten end points measured during the 12 months before and 12 months after baseline: hemoglobin A1c (HbA1c); hypoglycemia (emergency department or hospital utilization); hyperglycemia (emergency department or hospital utilization); HbA1c levels lower than 7%, lower than 8%, and higher than 9%; 1 emergency department encounter or more for any reason; 1 hospitalization or more for any reason; and number of outpatient visits and telephone visits. Results: The real-time CGM initiators included 3806 patients (mean age, 42.4 years [SD, 19.9 years]; 51% female; 91% type 1, 9% type 2); the noninitiators included 37 947 patients (mean age, 63.4 years [SD, 13.4 years]; 49% female; 6% type 1, 94% type 2). The prebaseline mean HbA1c was lower among real-time CGM initiators than among noninitiators, but real-time CGM initiators had higher prebaseline rates of hypoglycemia and hyperglycemia. Mean HbA1c declined among real-time CGM initiators from 8.17% to 7.76% and from 8.28% to 8.19% among noninitiators (adjusted difference-in-differences estimate, -0.40%; 95% CI, -0.48% to -0.32%; P < .001). Hypoglycemia rates declined among real-time CGM initiators from 5.1% to 3.0% and increased among noninitiators from 1.9% to 2.3% (difference-in-differences estimate, -2.7%; 95% CI, -4.4% to -1.1%; P = .001). There were also statistically significant differences in the adjusted net changes in the proportion of patients with HbA1c lower than 7% (adjusted difference-in-differences estimate, 9.6%; 95% CI, 7.1% to 12.2%; P < .001), lower than 8% (adjusted difference-in-differences estimate, 13.1%; 95% CI, 10.2% to 16.1%; P < .001), and higher than 9% (adjusted difference-in-differences estimate, -7.1%; 95% CI, -9.5% to -4.6%; P < .001) and in the number of outpatient visits (adjusted difference-in-differences estimate, -0.4; 95% CI, -0.6 to -0.2; P < .001) and telephone visits (adjusted difference-in-differences estimate, 1.1; 95% CI, 0.8 to 1.4; P < .001). Initiation of real-time CGM was not associated with statistically significant changes in rates of hyperglycemia, emergency department visits for any reason, or hospitalizations for any reason. Conclusions and Relevance: In this retrospective cohort study, insulin-treated patients with diabetes selected by physicians for real-time continuous glucose monitoring compared with noninitiators had significant improvements in hemoglobin A1c and reductions in emergency department visits and hospitalizations for hypoglycemia, but no significant change in emergency department visits or hospitalizations for hyperglycemia or for any reason. Because of the observational study design, findings may have been susceptible to selection bias.

Effect of Out-of-Pocket Cost on Medication Initiation, Adherence, and Persistence among Patients with Type 2 Diabetes: The Diabetes Study of Northern California (DISTANCE).

OBJECTIVE: To estimate the effect of out-of-pocket (OOP) cost on nonadherence to classes of cardiometabolic medications among patients with diabetes. DATA SOURCES/SETTING: Electronic health records from a large, health care delivery system for 223,730 patients with diabetes prescribed 842,899 new cardiometabolic medications during 2006-2012. STUDY DESIGN: Observational, new prescription cohort study of the effect of OOP cost on medication initiation and adherence. DATA COLLECTION: Adherence and OOP costs were based on pharmacy dispensing records and benefits. PRINCIPAL FINDINGS: Primary nonadherence (never dispensed) increased monotonically with OOP cost after adjusting for demographics, neighborhood socioeconomic status, Medicare, medical financial assistance, OOP maximum, deductibles, mail order pharmacy incentive and use, drug type, generic or brand, day's supply, and comorbidity index; 7 percent were never dispensed the new medication when OOP cost ≥$11, 5 percent with OOP cost of $1-$10, and 3 percent when the medication was free of charge (p < .0001). Higher OOP cost was also strongly associated with inadequate secondary adherence (≥20 percent of time without adequate medication). There was no clinically significant or consistent relationship between OOP costs and early nonpersistence (dispensed once, never refilled) or later stage nonpersistence (discontinued within 24 months). CONCLUSIONS: Cost-sharing may deter clinically vulnerable patients from initiating essential medications, undermining adherence and risk factor control.

Association of Patient-Physician Language Concordance and Glycemic Control for Limited-English Proficiency Latinos With Type 2 Diabetes.

Importance: Providing culturally competent care to the growing number of limited-English proficiency (LEP) Latinos with diabetes in the United States is challenging. Objective: To evaluate changes in risk factor control among LEP Latinos with diabetes who switched from language-discordant (English-only) primary care physicians (PCPs) to language-concordant (Spanish-speaking) PCPs or vice versa. Design, Setting, and Participants: This pre-post, difference-in-differences study selected 1605 adult patients with diabetes who self-identified as Latino, whose preferred language was Spanish, and who switched PCPs between January 1, 2007, and December 31, 2013. Study participants were members of the Kaiser Permanente Northern California health care system (an integrated health care delivery system with access to bilingual PCPs and/or professional interpreter services). Spanish-speaking and English-only PCPs were identified by self-report or utilization data. Exposures: Change in patient-PCP language concordance after switching PCPs. Main Outcomes and Measures: Glycemic control (glycated hemoglobin [HbA1c] < 8%), poor glycemic control (HbA1c > 9%), low-density-lipoprotein (LDL) control (LDL < 100 mg/dL), and systolic blood pressure (SBP) control (SBP < 140 mm Hg). Results: Overall, 1605 LEP Latino adults with diabetes (mean [SD] age, 60.5 [13.1] years) were included in this study, and there was a significant net improvement in glycemic and LDL control among patients who switched from language-discordant PCPs to concordant PCPs relative to those who switched from one discordant PCP to another discordant PCP. After adjustment and accounting for secular trends, the prevalence of glycemic control increased by 10% (95% CI, 2% to 17%; P = .01), poor glycemic control decreased by 4% (95% CI, -10% to 2%; P = .16) and LDL control increased by 9% (95% CI, 1% to 17%; P = .03). No significant changes were observed in SBP control. Prevalence of LDL control increased 15% (95% CI, 7% to 24%; P < .001) among LEP Latinos who switched from concordant to discordant PCPs. Risk factor control did not worsen following a PCP switch in any group. Conclusions and Relevance: We observed significant improvements in glycemic control among LEP Latino patients with diabetes who switched from language-discordant to concordant PCPs. Facilitating language-concordant care may be a strategy for diabetes management among LEP Latinos.

Identifying Spanish Language Competent Physicians: The Diabetes Study of Northern California (DISTANCE).

OBJECTIVES: Language barriers negatively impact health care access and quality for US immigrants. Latinos are the second largest immigrant group and the largest, fastest growing minority. Health care systems need simple, low cost and accurate tools that they can use to identify physicians with Spanish language competence. We sought to address this need by validating a simple and low-cost tool already in use in a major health plan. DESIGN SETTING PARTICIPANTS: A web-based survey conducted in 2012 among physicians caring for patients in a large, integrated health care delivery system. Of the 2,198 survey respondents, 111 were used in additional analysis involving patient report of those physicians' fluency. MAIN OUTCOME MEASURES: We compared health care physicians' responses to a single item, Spanish language self-assessment tool (measuring "medical proficiency") with patient-reported physician language competence, and two validated physician self-assessment tools (measuring "fluency" and "confidence"). RESULTS: Concordance between medical proficiency was moderate with patient reports (weighted Kappa .45), substantial with fluency (weighted Kappa .76), and moderate-to-substantial with confidence (weighted Kappas .53 to .66). CONCLUSIONS: The single-question self-reported medical proficiency tool is a low-cost tool useful for quickly identifying Spanish competent physicians and is potentially suitable for use in clinical settings. A reasonable approach for health systems is to designate only those physicians who self-assess their Spanish medical proficiency as "high" as competent to provide care without an interpreter.

Financial Strain and Medication Adherence among Diabetes Patients in an Integrated Health Care Delivery System: The Diabetes Study of Northern California (DISTANCE).

OBJECTIVE: To examine self-reported financial strain in relation to pharmacy utilization adherence data. DATA SOURCES/STUDY SETTING: Survey, administrative, and electronic medical data from Kaiser Permanente Northern California. STUDY DESIGN: Retrospective cohort design (2006, n = 7,773). DATA COLLECTION/EXTRACTION METHODS: We compared survey self-reports of general and medication-specific financial strain to three adherence outcomes from pharmacy records, specifying adjusted generalized linear regression models. PRINCIPAL FINDINGS: Eight percent and 9 percent reported general and medication-specific financial strain. In adjusted models, general strain was significantly associated with primary nonadherence (RR = 1.37; 95 percent CI: 1.04-1.81) and refilling late (RR = 1.34; 95 percent CI: 1.07-1.66); and medication-specific strain was associated with primary nonadherence (RR = 1.42, 95 percent CI: 1.09-1.84). CONCLUSIONS: Simple, minimally intrusive questions could be used to identify patients at risk of poor adherence due to financial barriers.

Reach and Validity of an Objective Medication Adherence Measure Among Safety Net Health Plan Members with Diabetes: A Cross-Sectional Study.

BACKGROUND: With the expansion of Medicaid and low-cost health insurance plans among diverse patient populations, objective measures of medication adherence using pharmacy claims could advance clinical care and translational research for safety net care. However, safety net patients may experience fluctuating prescription drug coverage, affecting the performance of adherence measures. OBJECTIVE: To evaluate the performance of continuous medication gap (CMG) for diverse, low-income managed care members with diabetes. METHODS: We conducted this cross-sectional analysis using administrative and clinical data for 680 members eligible for a self-management support trial at a nonprofit, government-sponsored managed care plan. We applied CMG methodology to cardiometabolic medication claims for English- , Cantonese- , or Spanish-speaking members with diabetes. We examined inclusiveness (the proportion with calculable CMG) and selectivity (sociodemographic and medical differences from members without CMG). For validity, we examined unadjusted associations of suboptimal adherence (CMG > 20%) with suboptimal cardiometabolic control. RESULTS: 429 members (63%) had calculable CMG. Compared with members without CMG, members with CMG were younger, more likely employed, and had poorer glycemic control but had better blood pressure and lipid control. Suboptimal adherence occurred more frequently among members with poor cardiometabolic control than among members with optimal control (28% vs. 12%, P = 0.02). CONCLUSIONS: CMG demonstrated acceptable inclusiveness and validity in a diverse, low-income safety net population, comparable with its performance in studies among other insured populations. CMG may provide a useful tool to measure adherence among increasingly diverse Medicaid populations, complemented by other strategies to reach those not captured by CMG.

Ethnic Differences in Geriatric Conditions and Diabetes Complications Among Older, Insured Adults With Diabetes: The Diabetes and Aging Study.

OBJECTIVE: The aim of this study was to evaluate ethnic differences in burden of prevalent geriatric conditions and diabetic complications among older, insured adults with diabetes. METHOD: An observational study was conducted among 115,538 diabetes patients, aged ≥60, in an integrated health care system with uniform access to care. RESULTS: Compared with Whites, Asians and Filipinos were more likely to be underweight but had substantively lower prevalence of falls, urinary incontinence, polypharmacy, depression, and chronic pain, and were least likely of all groups to have at least one geriatric condition. African Americans had significantly lower prevalence of incontinence and falls, but higher prevalence of dementia; Latinos had a lower prevalence of falls. Except for end-stage renal disease (ESRD), Whites tended to have the highest rates of prevalent diabetic complications. DISCUSSION: Among these insured older adults, ethnic health patterns varied substantially; differences were frequently small and rates were often better among select minority groups, suggesting progress toward the Healthy People 2020 objective to reduce health disparities.

Impact of a pharmacy benefit change on new use of mail order pharmacy among diabetes patients: the Diabetes Study of Northern California (DISTANCE).

OBJECTIVE: To assess the impact of a pharmacy benefit change on mail order pharmacy (MOP) uptake. DATA SOURCES/STUDY SETTING: Race-stratified, random sample of diabetes patients in an integrated health care delivery system. STUDY DESIGN: In this natural experiment, we studied the impact of a pharmacy benefit change that conditionally discounted medications if patients used MOP and prepaid two copayments. We compared MOP uptake among those exposed to the benefit change (n = 2,442) and the reference group with no benefit change (n = 8,148), and estimated differential MOP uptake across social strata using a difference-in-differences framework. DATA COLLECTION/EXTRACTION METHODS: Ascertained MOP uptake (initiation among previous nonusers). PRINCIPAL FINDINGS: Thirty percent of patients started using MOP after receiving the benefit change versus 9 percent uptake among the reference group (p < .0001). After adjustment, there was a 26 percentage point greater MOP uptake (benefit change effect). This benefit change effect was significantly smaller among patients with inadequate health literacy (15 percent less), limited English proficiency (14 percent less), and among Latinos and Asians (24 and 16 percent less compared to Caucasians). CONCLUSIONS: Conditionally discounting medications delivered by MOP effectively stimulated MOP uptake overall, but it unintentionally widened previously existing social gaps in MOP use because it stimulated less MOP uptake in vulnerable populations.

Ethnic differences in appointment-keeping and implications for the patient-centered medical home--findings from the Diabetes Study of Northern California (DISTANCE).

OBJECTIVE: To examine ethnic differences in appointment-keeping in a managed care setting. DATA SOURCES/STUDY SETTING: Kaiser Permanente Diabetes Study of Northern California (DISTANCE), 2005-2007, n = 12,957. STUDY DESIGN: Cohort study. Poor appointment-keeping (PAK) was defined as missing >1/3 of planned, primary care appointments. Poisson regression models were used to estimate ethnic-specific relative risks of PAK (adjusting for demographic, socio-economic, health status, and facility effects). DATA COLLECTION/EXTRACTION METHODS: Administrative/electronic health records and survey responses. PRINCIPAL FINDINGS: Poor appointment-keeping rates differed >2-fold across ethnicities: Latinos (12 percent), African Americans (10 percent), Filipinos (7 percent), Caucasians (6 percent), and Asians (5 percent), but also varied by medical center. Receiving >50 percent of outpatient care via same-day appointments was associated with a 4-fold greater PAK rate. PAK was associated with 20, 30, and 40 percent increased risk of elevated HbA1c (>7 percent), low-density lipoprotein (>100 mm/dl), and systolic blood pressure (>130 mmHg), respectively. CONCLUSIONS: Latinos and African Americans were at highest risk of missing planned primary care appointments. PAK was associated with a greater reliance on same-day visits and substantively poorer clinical outcomes. These results have important implications for public health and health plan policy, as primary care rapidly expands toward open access to care supported by the patient-centered medical home model.

Adherence to laboratory test requests by patients with diabetes: the Diabetes Study of Northern California (DISTANCE).

OBJECTIVES: To estimate rates and predictors of clinical laboratory test completion by patients with diabetes after provider referral. STUDY DESIGN: Prospective cohort study. METHODS: Among 186,306 adult members with diabetes in Kaiser Permanente Northern California, we searched the electronic medical records (July 1, 2008, to June 30, 2009) of each patient for the first outpatient order to obtain the following laboratory tests commonly used to measure risk factor control or adverse effects of pharmacotherapy: levels of glycosylated hemoglobin, low density lipoprotein cholesterol, serum creatinine, urinary albumin, or creatine kinase (the latter only among persons using statins). We measured laboratory test attendance as completion of an order (including time to results) within 6 months of the referral date and looked for variations by subgroups. RESULTS: Laboratory test attendance ranged from 86% for glycosylated hemoglobin level to 73% for serum creatinine level. Time to laboratory test attendance was a median of 7 to 11 days and a mean of 25 to 30 days. Laboratory test attendance was more likely for women and older patients or for orders after a face-to-face provider visit and was less likely for orders by a pharmacist. However, most variations (even by laboratory copayment) were small or not clinically substantive. In subanalyses, we observed no clinically significant variations by race/ethnicity, socioeconomic status, trust in provider, or patient-provider communication and found no association with depressive symptoms, health literacy, or English fluency. CONCLUSION: The fact that 1 in 7 patients did not complete laboratory tests within 6 months of the provider referral may help explain why healthcare services seem to fall short of optimal diabetes care.

Mail-order pharmacy use and adherence to diabetes-related medications.

OBJECTIVE: To investigate whether patients who use mail-order pharmacies were more likely to have good medication adherence than patients who use local pharmacies. STUDY DESIGN: Cross-sectional investigation. METHODS: We conducted cross-sectional analyses of patients from the Kaiser Permanente Northern California (KPNC) diabetes registry who received a new antiglycemic, antihypertensive, or lipid-lowering index medication between January 1, 2006, and May 31, 2006. We defined good adherence as medication availability at least 80% of the time (ie, a continuous measure of medication gaps value of < or = 20%) and compared adherence between mail-order users (> or = 66% of refills by mail) and KPNC local pharmacy users (all refills in person). Adherence was calculated from the initial dispensing through 15 months of follow-up, medication discontinuation, or May 31, 2007, whichever came first. We analyzed the data using multivariate logistic regression models, after determining that unmeasured patient-level factors and self-selection did not significantly bias our analyses. RESULTS: A total of 13,922 eligible patients refilled an index medication. Compared with those who used only local KPNC pharmacies, patients who received medications by mail were more likely to have good adherence (84.7% vs 76.9%, P <.001). After adjusting for potential confounders, including days' supply and out-of-pocket costs, mailorder users had better adherence to antiglycemic, antihypertensive, and lipid-lowering medications (P <.001 for all). CONCLUSIONS: Compared with patients who obtained medication refills at local pharmacies, patients who received them by mail were more likely to have good adherence. The association between mail-order use and medication adherence should be evaluated in a randomized clinical trial.

New prescription medication gaps: a comprehensive measure of adherence to new prescriptions.

OBJECTIVE: Describe a novel approach to comprehensively summarize medication adherence. DATA SOURCES/STUDY SETTING: Kaiser Permanente Northern California Diabetes Registry (n approximately 220,000) STUDY DESIGN: In a new prescription cohort design (27,329 subjects prescribed new medications), we used pharmacy utilization data to estimate adherence during 24 months follow-up. Proportion of time without sufficient medications (medication gaps) was estimated using a novel measure (New Prescription Medication Gaps [NPMG]) and compared with a traditional measure of adherence. DATA COLLECTION/EXTRACTION METHODS: Data derived from electronic medical records and survey responses. PRINCIPAL FINDINGS: Twenty-two percent of patients did not become ongoing users (had zero or only one dispensing of the new prescription). The proportion of newly prescribed patients that never became ongoing users was eightfold greater than the proportion who maintained ongoing use, but with inadequate adherence. Four percent of those with at least two dispensings discontinued therapy during the 24 months follow-up. NPMG was significantly associated with high out-of-pocket costs, self-reported adherence, and clinical response to therapy. CONCLUSIONS: NPMG is a valid adherence measure. Findings also suggest a larger burden of inadequate adherence than previously thought. Public health efforts have traditionally focused on improving adherence in ongoing users; clearly more attention is needed to address nonpersistence in the very first stages after a new medication is prescribed.

Effect of cost-sharing changes on self-monitoring of blood glucose.

OBJECTIVE: To study the effect of cost-sharing policy changes on utilization of test strips for self-monitoring of blood glucose. STUDY DESIGN: A legislative mandate (January 1, 2000) required California health plans to cover diabetes supplies, including those for self-monitoring of blood glucose. One health plan, Kaiser Permanente Northern California, initially waived established copayments and provided free test strips to members with diabetes mellitus for 2 years but later instituted a 20% coinsurance charge for a portion of their membership. METHODS: A retrospective cohort design was used to study pharmacy-based estimates of test strip utilization changes during this natural experiment. Analyses included 2 cohort investigations using pretest-posttest analysis with control subjects to study transitions from a copayment period to a free test strip period and from the free test strip period to a coinsurance period. RESULTS: During the copayment period, test strip utilization was inversely related to copayments for test strips. Offering free test strips did not increase utilization, even among those paying higher copayments before the policy change. Price-elastic patterns formed before and during the copayment period persisted, despite receiving free test strips for 2 years. The coinsurance, introduced after 2 years of receiving free test strips, resulted in statistically significant (but not clinically relevant) decreased utilization (approximately 1-3 fewer test strips/month). Change patterns did not differ by socioeconomic status. CONCLUSIONS: Offering free test strips shifted costs from patient to health plan, without improving adherence. The introduced coinsurance slightly reduced utilization and adherence to recommendations about self-monitoring of blood glucose. Neither intervention had marked clinical effect. Cross-sectional analyses should not be used to predict utilization changes in the face of rapidly evolving benefit policies.

Achieving good glycemic control: initiation of new antihyperglycemic therapies in patients with type 2 diabetes from the Kaiser Permanente Northern California Diabetes Registry.

OBJECTIVE: To compare the effectiveness of antihyperglycemic therapies in type 2 diabetic patients with poor glycemic control (baseline glycosylated hemoglobin [HbA1C] > 8%). STUDY DESIGN: Longitudinal (cohort) study. METHODS: Study patients were 4775 type 2 diabetic patients who initiated new antihyperglycemic therapies and maintained them for up to 1 year. The study setting was Kaiser Permanente Northern California Medical Group, an integrated, prepaid, healthcare delivery organization. Treatment regimens were 1 or more of the following: insulin, thiazolidinediones, sulfonylureas, biguanides (metformin), or other less frequently used options (including meglitinides or alpha-glucosidase inhibitors). RESULTS: In this cohort, the mean HbA1C was 9.9% when therapy was initiated. Within 1 year, there was a drop of 1.3 percentage points in the mean HbA1C (to 8.6%), and 18% of new initiators achieved HbA1C values of < or = 7%. After adjusting for baseline clinical differences, the proportion of patients treated to goal was greatest among those receiving thiazolidinediones in combination (24.6%-25.7%) or a regimen of metformin and insulin (24.9%), while the least success was experienced by those receiving sulfonylureas alone (12.5%) or insulin-sulfonylureas regimens (10.9%). The probability of achieving the target goal was most strongly predicted by the level of glycemic control before initiation, but patient behaviors (eg, frequent self-monitoring, lower rates of missed appointments) also were strongly associated with greater levels of control. CONCLUSION: Overall, therapy initiation resulted in an impressive population-level benefit. However, since most new initiators still had not achieved good control within 12 months, careful monitoring and prompt therapy intensification remain important.

Missed appointments and poor glycemic control: an opportunity to identify high-risk diabetic patients.

OBJECTIVE: When patients miss scheduled medical appointments, continuity and effectiveness of healthcare delivery is reduced, appropriate monitoring of health status lapses, and the cost of health services increases. We evaluated the relationship between missed appointments and glycemic control (glycosylated hemoglobin or HbA1c) in a large, managed care population of diabetic patients. RESEARCH DESIGN AND METHODS: Missed appointment rate was related cross-sectionally to glycemic control among 84,040 members of the Kaiser Permanente Northern California Diabetes Registry during 2000. Adjusted least-square mean estimates of HbA1c were derived by level of appointment keeping (none missed, 1-30% missed, and >30% missed appointments for the calendar year) stratified by diabetes therapy. RESULTS: Twelve percent of the subjects missed more than 30% of scheduled appointments during 2000. Greater rates of missed appointments were associated with significantly poorer glycemic control after adjusting for demographic factors (age, sex), clinical status, and health care utilization. The adjusted mean HbA1c among members who missed >30% of scheduled appointments was 0.70 to 0.79 points higher (P <0.0001) relative to those attending all appointments. Patients who missed more than 30% of their appointments were less likely to practice daily self-monitoring of blood glucose and to have poor oral medication refill adherence. CONCLUSION: Patients who underuse care lack recorded information needed to determine level of risk. Frequently missed appointments were associated with poorer glycemic control and suboptimal diabetes self-management practice, are readily ascertained in clinical settings, and therefore could have clinical utility as a risk-stratifying criterion indicating the need for targeted case management.