Stanley Xu

Association of online patient access to clinicians and medical records with use of clinical services.

CONTEXT Prior studies suggest that providing patients with online access to health records and e-mail communication with physicians may substitute for traditional health care services. OBJECTIVE To assess health care utilization by both users and nonusers of online access to health records before and after initiation of MyHealthManager (MHM), a patient online access system. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of the use of health care services by members (≥18 years old) who were continuously enrolled for at least 24 months during the study period March 2005 through June 2010 in Kaiser Permanente Colorado, a group model, integrated health care delivery system. Propensity scores (using age, sex, utilization frequencies, and chronic illnesses) were used for cohort matching. Unadjusted utilization rates were calculated for both MHM users and nonusers and were the basis for difference-of-differences analyses. We also used generalized estimating equations to compare the adjusted rates of utilization of health care services before and after online access. MAIN OUTCOME MEASURES Rates of office visits, telephone encounters, after-hours clinic visits, emergency department encounters, and hospitalizations between members with and without online access. RESULTS Comparing the unadjusted rates for use of clinical services before and after the index date between the matched cohorts, there was a significant increase in the per-member rates of office visits (0.7 per member per year; 95% CI, 0.6-0.7; P < .001) and telephone encounters (0.3 per member per year; 95% CI, 0.2-0.3; P < .001). There was also a significant increase in per-1000-member rates of after-hours clinic visits (18.7 per 1000 members per year; 95% CI, 12.8-24.3; P < .001), emergency department encounters (11.2 per 1000 members per year; 95% CI, 2.6-19.7; P = .01), and hospitalizations (19.9 per 1000 members per year; 95% CI, 14.6-25.3; P < .001) for MHM users vs nonusers. CONCLUSION Having online access to medical records and clinicians was associated with increased use of clinical services compared with group members who did not have online access.

Use of Stabilized Inverse Propensity Scores as Weights to Directly Estimate Relative Risk and Its Confidence Intervals

OBJECTIVES Inverse probability of treatment weighting (IPTW) has been used in observational studies to reduce selection bias. For estimates of the main effects to be obtained, a pseudo data set is created by weighting each subject by IPTW and analyzed with conventional regression models. Currently, variance estimation requires additional work depending on type of outcomes. Our goal is to demonstrate a statistical approach to directly obtain appropriate estimates of variance of the main effects in regression models. METHODS We carried out theoretical and simulation studies to show that the variance of the main effects estimated directly from regressions using IPTW is underestimated and that the type I error rate is higher because of the inflated sample size in the pseudo data. The robust variance estimator using IPTW often slightly overestimates the variance of the main effects. We propose to use the stabilized weights to directly estimate both the main effect and its variance from conventional regression models. RESULTS We applied the approach to a study examining the effectiveness of serum potassium monitoring in reducing hyperkalemia-associated adverse events among 27,355 diabetic patients newly prescribed with a renin-angiotensin-aldosterone system inhibitor. The incidence rate ratio (with monitoring vs. without monitoring) and confidence intervals were 0.46 (0.34, 0.61) using the stabilized weights compared with 0.46 (0.38, 0.55) using typical IPTW. CONCLUSIONS Our theoretical, simulation results and real data example demonstrate that the use of the stabilized weights in the pseudo data preserves the sample size of the original data, produces appropriate estimation of the variance of main effect, and maintains an appropriate type I error rate.

Risk of immune thrombocytopenic purpura after measles-mumps-rubella immunization in children.

BACKGROUND. The measles-mumps-rubella vaccine has been associated with immune thrombocytopenia purpura in 2 small studies. METHODS. By using the Vaccine Safety Datalink, we identified measles-mumps-rubella–vaccinated children aged 1 to 18. A case of immune thrombocytopenia purpura was defined as a patient with a platelet count of ≤50000/μL with clinical bleeding and normal red and white blood cell indices. The immune thrombocytopenia purpura incidence rates during exposed (42 days after vaccination) and unexposed time periods were determined. A retrospective cohort of vaccinated children was used to determine incident rate ratios for children aged 1 to 18 years, 12 to 23 months, and 12 to 15 months. RESULTS. A total of 1036689 children received 1107814 measles-mumps-rubella vaccinations; there were 259 confirmed patients with immune thrombocytopenia purpura. Because only 5 exposed cases occurred after age 2, analyses were limited to children aged 12 to 23 months. Exposed patients aged 12 to 23 months had lower median platelet counts than those who were unexposed and had similar median duration of illness (11 vs 10 days). The incident rate ratio was highest for children aged 12 to 15 months at 7.10. The incident rate ratio for boys aged 12 to 15 months was 14.59, and the incident rate ratio for girls in the same age group was 3.22. Seventy-six percent of immune thrombocytopenia purpura cases in children aged 12 to 23 months were attributable to measles-mumps-rubella vaccination. This vaccine causes 1 case of immune thrombocytopenia purpura per every 40000 doses. CONCLUSION. Measles-mumps-rubella vaccine that is given in the second year of life is associated with an increased risk of immune thrombocytopenia purpura.

The Frequency and Behavioral Outcomes of Goal Choices in the Self-management of Diabetes

Purpose The purpose of this study was to determine the frequency and effectiveness of behavioral goal choices in the self-management of diabetes and to test goal-setting theory hypotheses that self-selection and behavioral specificity of goals are key to enhancing persistence. Methods Participants with type 2 diabetes in a randomized controlled trial (n = 422) completed baseline behavioral assessments using a clinic-based, interactive, self-management CD-ROM that allowed them to select a behavioral goal and receive mail and telephone support for the initial 6 months of the trial followed by additional behavioral assessments. Frequency of behavioral goal selection and 6-month behavioral data were collected. Results Approximately 49%, 27%, and 24% of the participants, respectively, set goals to increase physical activity (PA), reduce fat intake, or increase fruits and vegetables (F&V) consumed. At baseline, participants who selected PA, reduced fat consumption, or F&V were significantly, and respectively, less active, consumed more dietary fat, and ate fewer F&V regardless of demographic characteristics. Participants who selected a reduced-fat goal showed a significantly larger decrease than did those that selected PA or F&V goals. Participants who selected an F&V goal showed significant changes in F&V consumption. Participants who selected a PA goal demonstrated significant changes in days of moderate and vigorous physical activity. Conclusions When participants are provided with information on health behavior status and an option of behavioral goals for managing type 2 diabetes, they will select personally appropriate goals, resulting in significant behavioral changes over a 6-month period.

Association between parental depression and children's health care use.

OBJECTIVE. The objective of this study was to determine the association between parental depression and pediatric health care use patterns. METHODS. We selected all children who were 0 to 17 years of age, enrolled in Kaiser Permanente of Colorado during the study period July 1997 to December 2002, and linked to at least 1 parent/subscriber who was enrolled for at least 6 months during that period. Unexposed children were selected from a pool of children whose parents did not have a depression diagnosis. Outcome measures were derived from the childs payment files and electronic medical charts and included 5 categories of use: well-child-care visits, sick visits to primary care departments, specialty clinic visits, emergency department visits, and inpatient visits. We compared the rate of use per enrollment month for these 5 categories between exposed and unexposed children within each of the 5 age strata. RESULTS. Our study population had 24391 exposed and 45274 age-matched, unexposed children. For the outcome of well-child-care visits, teenagers showed decreased rates of visits among exposed children. The rate of specialty department visits was higher in exposed children in the 4 oldest age groups. The rates of both emergency department visits and sick visits to primary care departments were higher for exposed children across all 5 age categories. The rate of inpatient visits was higher among exposed children in 2 of the 5 age groups. CONCLUSIONS. Overall, having at least 1 depressed parent is associated with greater rate of emergency department and sick visits across all age groups, greater use of inpatient and specialty services in some age groups, and a lower rate of well-child-care visits among 13- to 17-year-olds. This pattern of increased use of expensive resources and decreased use of preventive services represents one of the hidden costs of adult depression.

Trends in Diabetes Incidence Among 7 Million Insured Adults, 2006–2011 The SUPREME-DM Project

An observational cohort analysis was conducted within the Surveillance, Prevention, and Management of Diabetes Mellitus (SUPREME-DM) DataLink, a consortium of 11 integrated health-care delivery systems with electronic health records in 10 US states. Among nearly 7 million adults aged 20 years or older, we estimated annual diabetes incidence per 1,000 persons overall and by age, sex, race/ethnicity, and body mass index. We identified 289,050 incident cases of diabetes. Age- and sex-adjusted population incidence was stable between 2006 and 2010, ranging from 10.3 per 1,000 adults (95% confidence interval (CI): 9.8, 10.7) to 11.3 per 1,000 adults (95% CI: 11.0, 11.7). Adjusted incidence was significantly higher in 2011 (11.5, 95% CI: 10.9, 12.0) than in the 2 years with the lowest incidence. A similar pattern was observed in most prespecified subgroups, but only the differences for persons who were not white were significant. In 2006, 56% of incident cases had a glycated hemoglobin (hemoglobin A1c) test as one of the pair of events identifying diabetes. By 2011, that number was 74%. In conclusion, overall diabetes incidence in this population did not significantly increase between 2006 and 2010, but increases in hemoglobin A1c testing may have contributed to rising diabetes incidence among nonwhites in 2011.

Increased Risk of Bleeding in Patients on Clopidogrel Therapy After Drug-Eluting Stents Implantation Insights From the HMO Research Network-Stent Registry (HMORN-Stent)

Background—Studies suggest that extended clopidogrel use after drug-eluting stent (DES) implantation may decrease the risk of myocardial infarction (MI) and death. Little is known about the competing risk of bleeding from clopidogrel in “real world” clinical practice. Methods and Results—We studied 7689 patients undergoing drug-eluting stent implantation enrolled in the HMO Research Network-Stent Registry between 2004 and 2007. Patients were analyzed in 6-month intervals for the occurrence of major bleeding, MI, and death. Clopidogrel use was determined by pharmacy dispensing data. Regression models assessed the association between clopidogrel use and outcomes. Overall, 3603 patients (49.1%) received clopidogrel for >6 months. During a mean follow-up of 418 days (SD, ±168 days), 217 (2.9%) patients died, 279 (3.7%) had a MI, and 271 (3.6%) had major bleeding. After adjustment, patients on clopidogrel therapy were associated with increased major bleeding in all time intervals (0 to 6 months: relative risk (RR)=2.70, 95% CI=1.41 to 5.19; 7 to 12 months: RR=1.71, 95% CI=1.05 to 2.79; 13 to 18 months: RR=2.34, 95% CI=1.26 to 4.34), compared with patients off clopidogrel. Clopidogrel use was also associated with decreased risk of MI for all time intervals (0 to 6 months: RR=0.52, 95% CI=0.36 to 0.77; 7 to 12 months: RR=0.46, 95% CI=0.30 to 0.70; 13 to 18 months: RR=0.53, 95% CI=0.29 to 0.99) and decreased death in the 7 to 12 month interval (RR=0.50, 95% CI=0.30 to 0.83). Conclusions—Clopidogrel use was associated with increased major bleeding and decreased MI persisting to 18 months. Bleeding risks on clopidogrel therapy deserve consideration in the ongoing debate regarding optimal clopidogrel duration after PCI.

The Association Between Rural Residence and the Use, Type, and Quality of Depression Care

OBJECTIVE To assess the association between rurality and depression care. METHODS Data were extracted for 10,319 individuals with self-reported depression in the Medical Expenditure Panel Survey. Pharmacotherapy was defined as an antidepressant prescription fill, and minimally adequate pharmacotherapy was defined as receipt of at least 4 antidepressant fills. Psychotherapy was defined as an outpatient counseling visit, and minimally adequate psychotherapy was defined as > or = 8 visits. Rurality was defined using Metropolitan Statistical Areas (MSAs) and Rural Urban Continuum Codes (RUCCs). RESULTS Over the year, 65.1% received depression treatment, including 58.8% with at least 1 antidepressant prescription fill and 24.5% with at least 1 psychotherapy visit. Among those in treatment, 56.2% had minimally adequate pharmacotherapy treatment and 36.3% had minimally adequate psychotherapy treatment. Overall, there were no significant rural-urban differences in receipt of any type of formal depression treatment. However, rural residence was associated with significantly higher odds of receiving pharmacotherapy (MSA: OR 1.16 [95% CI, 1.01-1.34; P= .04] and RUCC: OR 1.04 [95% CI, 1.00-1.08; P= .05]), and significantly lower odds of receiving psychotherapy (MSA: OR 0.62 [95% CI, 0.53-0.74; P < .01] and RUCC: OR 0.91 [95% CI, 0.88-0.94; P < .001]). Rural residence was not significantly associated with the adequacy of pharmacotherapy, but it was significantly associated with the adequacy of psychotherapy (MSA: OR 0.53 [95% CI, 0.41-0.69; P < .01] and RUCC: OR 0.92 [95% CI, 0.86-0.99; P= .02]). Psychiatrists per capita were a mediator in the psychotherapy analyses. CONCLUSIONS Rural individuals are more reliant on pharmacotherapy than psychotherapy. This may be a concern if individuals in rural areas turn to pharmacotherapy because psychotherapists are unavailable rather than because they have a preference for pharmacotherapy.

Pragmatic Trial of Health Care Technologies to Improve Adherence to Pediatric Asthma Treatment: A Randomized Clinical Trial

IMPORTANCE Most patients with asthma take fewer than half of prescribed doses of controller medication. Interventions to improve adherence have typically been costly, impractical, and at best only minimally successful. OBJECTIVE To test a speech recognition (SR) intervention to improve adherence to pediatric asthma controller medication. DESIGN, SETTING, AND PARTICIPANTS The Breathe Well study was a 24-month pragmatic randomized clinical trial. The study was conducted within Kaiser Permanente Colorado, a large, group-model health maintenance organization. A total of 1187 children aged 3 to 12 years with a persistent asthma diagnosis and prescription for an inhaled corticosteroid were randomized to the computerized SR intervention or usual care condition and followed up for 24 months between October 2009 and February 2013. INTERVENTIONS Speech recognition telephone calls to parents in the intervention condition were triggered when an inhaled corticosteroid refill was due or overdue. Calls were automatically tailored with medical and demographic information from the electronic health record and from parent answers to questions in the call regarding recent refills or a desire to receive help refilling, learn more about asthma control, or speak with an asthma nurse or pharmacy staff member. MAIN OUTCOMES AND MEASURES Adherence to pediatric asthma controller medication, measured as the medication possession ratio over 24 months. RESULTS In the intention-to-treat analysis, inhaled corticosteroid adherence was 25.4% higher in the intervention group than in the usual care group (24-month mean [SE] adherence, 44.5% [1.2%] vs 35.5% [1.1%], respectively; P < .001). Asthma-related urgent care events did not differ between the 2 groups. The intervention effect was consistent in subgroups stratified by age, sex, race/ethnicity, body mass index, and disease-related characteristics. CONCLUSIONS AND RELEVANCE The interventions significant impact on adherence demonstrates strong potential for low-cost SR adherence programs integrated with an electronic health record. The absence of change in urgent care visits may be attributable to the already low number of asthma urgent care visits within Kaiser Permanente Colorado. Application of electronic health record-leveraged SR interventions may reduce health care utilization when applied in a population with less-controlled asthma. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00958932.

Comparison of epidemiologic methods for active surveillance of vaccine safety

OBJECTIVE We performed a simulation study to compare four study designs [(matched-cohort, vaccinated-only (risk-interval) cohort, case-control, and self-controlled case-series (SCCS)] in the context of vaccine safety active surveillance. METHODS For each combination of various incidence levels (3, 30, 300 per 10(5) person-years) and relative risks (RR 1.5-18), 100 case sets were infused into the cohort, matching 10(5) vaccinated to 10(5) unvaccinated on age and gender. The matched-cohort was converted into weekly accumulated data intervals with the other three study design samples drawn from each. Analyses were with appropriate regression models. The signal detection time was the first week where the log likelihood ratio (LLR) exceeded the upper boundary from the MaxSPRT sequential analysis method. Empirical type I (false positive) and type II (power) error rates and risk estimate bias were also calculated. RESULTS The matched-cohort design exhibited the shortest detection time, lowest false positive rate and highest empirical power followed by the risk-interval cohort, SCCS, and case-control. In most monitoring weeks, the risk estimate bias was smallest for the cohort, followed by the risk-interval, SCCS and case-control designs. CONCLUSIONS The cohort study design performed the best in the sequential analysis of active surveillance for vaccine safety. The risk-interval cohort and SCCS designs offer reasonable and efficient alternatives, especially if selection bias is a concern. Future research should address seasonality or age effects.