Comparative Effectiveness and Safety of Bariatric Procedures for Weight Loss: A PCORnet Cohort Study

BACKGROUND

There has been a dramatic shift in use of bariatric procedures, but little is known about their long-term comparative effectiveness.

OBJECTIVE

To compare weight loss and safety among bariatric procedures.

DESIGN

Retrospective observational cohort study, January 2005 to September 2015. (ClinicalTrials.gov: NCT02741674).

SETTING

41 health systems in the National Patient-Centered Clinical Research Network.

PARTICIPANTS

65 093 patients aged 20 to 79 years with body mass index (BMI) of 35 kg/m2 or greater who had bariatric procedures.

INTERVENTION

32 208 Roux-en-Y gastric bypass (RYGB), 29 693 sleeve gastrectomy (SG), and 3192 adjustable gastric banding (AGB) procedures.

MEASUREMENTS

Estimated percent total weight loss (TWL) at 1, 3, and 5 years; 30-day rates of major adverse events.

RESULTS

Total numbers of eligible patients with weight measures at 1, 3, and 5 years were 44 978 (84%), 20 783 (68%), and 7159 (69%), respectively. Thirty-day rates of major adverse events were 5.0% for RYGB, 2.6% for SG, and 2.9% for AGB. One-year mean TWLs were 31.2% (95% CI, 31.1% to 31.3%) for RYGB, 25.2% (CI, 25.1% to 25.4%) for SG, and 13.7% (CI, 13.3% to 14.0%) for AGB. At 1 year, RYGB patients lost 5.9 (CI, 5.8 to 6.1) percentage points more weight than SG patients and 17.7 (CI, 17.3 to 18.1) percentage points more than AGB patients, and SG patients lost 12.0 (CI, 11.6 to 12.5) percentage points more than AGB patients. Five-year mean TWLs were 25.5% (CI, 25.1% to 25.9%) for RYGB, 18.8% (CI, 18.0% to 19.6%) for SG, and 11.7% (CI, 10.2% to 13.1%) for AGB. Patients with diabetes, those with BMI less than 50 kg/m2, those aged 65 years or older, African American patients, and Hispanic patients lost less weight than patients without those characteristics.

LIMITATION

Potential unobserved confounding due to nonrandomized design; electronic health record databases had missing outcome data.

CONCLUSION

Adults lost more weight with RYGB than with SG or AGB at 1, 3, and 5 years; however, RYGB had the highest 30-day rate of major adverse events. Small subgroup differences in weight loss outcomes were observed.

PRIMARY FUNDING SOURCE

Patient-Centered Outcomes Research Institute.

Combining distributed regression and propensity scores: a doubly privacy-protecting analytic method for multicenter research

Purpose

Sharing of detailed individual-level data continues to pose challenges in multi-center studies. This issue can be addressed in part by using analytic methods that require only summary-level information to perform the desired multivariable-adjusted analysis. We examined the feasibility and empirical validity of 1) conducting multivariable-adjusted distributed linear regression and 2) combining distributed linear regression with propensity scores, in a large distributed data network.

Patients and methods

We compared percent total weight loss 1-year postsurgery between Roux-en-Y gastric bypass and sleeve gastrectomy procedure among 43,110 patients from 36 health systems in the National Patient-Centered Clinical Research Network. We adjusted for baseline demographic and clinical variables as individual covariates, deciles of propensity scores, or both, in three separate outcome regression models. We used distributed linear regression, a method that requires only summary-level information (specifically, sums of squares and cross products matrix) from sites, to fit the three ordinary least squares linear regression models. A comparison set of analyses that used pooled deidentified individual-level data from sites served as the reference.

Results

Distributed linear regression produced results identical to those from the corresponding pooled individual-level data analysis for all variables in all three models. The maximum numerical difference in the parameter estimate or standard error for all the variables was 3×10^-11 across three models.

Conclusion

Distributed linear regression analysis is a feasible and valid analytic method in multicenter studies for one-time continuous outcomes. Combining distributed regression with propensity scores via modeling offers more privacy protection and analytic flexibility.

Primary care physician resource use changes associated with feedback reports

OBJECTIVES

To measure changes in primary care physician (PCP) ordering rates for 4 global resource use measures before and after dissemination of physician feedback reports that provided peer-comparison resource use rates. We also explored whether physician practice characteristics (panel size, clinic size, and years of experience) were associated with resource use changes.

STUDY DESIGN

Pre-post implementation study measuring physician resource use in an integrated healthcare system (2011-2014).

METHODS

Kaiser Permanente Washington PCPs (N = 210) were provided annual feedback reports showing their personal ordering rates compared with those of their peers. Monthly physician ordering was measured from November 2011 to September 2014 (including prereport and postreport periods). We examined 4 physician ordering rates (specialty referrals, high-end imaging, laboratory tests, and 30-day prescriptions) per 1000 patients, adjusted for patient age, gender, and clinical complexity.

RESULTS

After accounting for physician practice characteristics, monthly PCP ordering rates for high-end imaging significantly decreased by 0.8 images per 1000 patients (P <.01). In contrast, orders for laboratory tests and 30-day prescriptions significantly increased by 15.0 tests and 84.7 prescriptions per 1000 patients (both P <.01). We observed greater changes following feedback in physicians with fewer years of experience (≤10 years), who had 4.2 fewer specialty referrals (P = .01) and 101.3 more 30-day prescriptions (P <.01) compared with those with more experience (>20 years).

CONCLUSIONS

Physician feedback reports may be associated with changes in physician resource use, and physicians with fewer years of experience may be more responsive to feedback reports. Better understanding of factors associated with changes in resource use is necessary for future targeted development of physician interventions.

Comparative effectiveness of bariatric procedures among adolescents: the PCORnet bariatric study

Background

Bariatric surgery has been used for treatment of severe obesity in adolescents but most studies have been small and limited in follow-up.

Objectives

We hypothesized that electronic health record data could be used to compare effectiveness of bariatric procedures in adolescents.

Setting

Data were obtained from clinical research networks using a common data model to extract data from each site.

Methods

Adolescents who underwent a primary bariatric procedure from 2005 through 2015 were identified. The percent change in body mass index (BMI) at 1, 3, and 5 years was estimated using random effects linear regression for patients undergoing all operations. Propensity score adjusted estimates and 95% confidence intervals were estimated for procedures with >25 patients at each time period.

Results

This cohort of 544 adolescents was predominantly female (79%) and White (66%), with mean (±standard deviation) age of 17.3 (±1.6) years and mean BMI of 49.8 (± 7.8) kg/m². Procedures included Roux-en-Y gastric bypass (RYGB; n = 177), sleeve gastrectomy (SG; n = 306), and laparoscopic adjustable gastric banding (n = 61). For those undergoing RYGB, SG, and laparoscopic adjustable gastric banding, mean (95% confidence interval) BMI changes of −31% (−30% to −33%), −28% (−27% to −29%), and −10% (−8% to −12%), were estimated at 1 year. For RYGB and SG, BMI changes of −29% (−26% to −33%) and −25% (−22% to −28%) were estimated at 3 years.

Conclusions

Adolescents undergoing SG and RYGB experienced greater declines in BMI at 1- and 3-year follow-up time points, while laparoscopic adjustable gastric banding was significantly less effective for BMI reduction. (Surg Obes Relat Dis 2018;000:1–13.)

The National Patient-Centered Clinical Research Network (PCORnet) Bariatric Study Cohort: Rationale, Methods, and Baseline Characteristics

Background

Although bariatric procedures are commonly performed in clinical practice, long-term data on the comparative effectiveness and safety of different procedures on sustained weight loss, comorbidities, and adverse effects are limited, especially in important patient subgroups (eg, individuals with diabetes, older patients, adolescents, and minority patients).

Objective

The objective of this study was to create a population-based cohort of patients who underwent 3 commonly performed bariatric procedures—adjustable gastric band (AGB), Roux-en-Y gastric bypass (RYGB), and sleeve gastrectomy (SG)—to examine the long-term comparative effectiveness and safety of these procedures in both adults and adolescents.

Methods

We identified adults (20 to 79 years old) and adolescents (12 to 19 years old) who underwent a primary (first observed) AGB, RYGB, or SG procedure between January 1, 2005 and September 30, 2015 from 42 health systems participating in the Clinical Data Research Networks within the National Patient-Centered Clinical Research Network (PCORnet). We extracted information on patient demographics, encounters with healthcare providers, diagnoses recorded and procedures performed during these encounters, vital signs, and laboratory test results from patients’ electronic health records (EHRs). The outcomes of interest included weight change, incidence of major surgery-related adverse events, and diabetes remission and relapse, collected for up to 10 years after the initial bariatric procedure.

Results

A total of 65,093 adults and 777 adolescents met the eligibility criteria of the study. The adult subcohort had a mean age of 45 years and was predominantly female (79.30%, 51,619/65,093). Among adult patients with non-missing race or ethnicity information, 72.08% (41,248/57,227) were White, 21.13% (12,094/57,227) were Black, and 20.58% (13,094/63,637) were Hispanic. The average highest body mass index (BMI) recorded in the year prior to surgery was 49 kg/m². RYGB was the most common bariatric procedure among adults (49.48%, 32,208/65,093), followed by SG (45.62%, 29,693/65,093) and AGB (4.90%, 3192/65,093). The mean age of the adolescent subcohort was 17 years and 77.5% (602/777) were female. Among adolescent patients with known race or ethnicity information, 67.3% (473/703) were White, 22.6% (159/703) were Black, and 18.0% (124/689) were Hispanic. The average highest recorded BMI in the year preceding surgery was 53 kg/m². The majority of the adolescent patients received SG (60.4%, 469/777), followed by RYGB (30.8%, 239/777) and AGB (8.9%, 69/777). A BMI measurement (proxy for follow-up) was available in 84.31% (44,978/53,351), 68.09% (20,783/30,521), and 68.56% (7159/10,442) of the eligible adult patients at 1, 3, and 5 years of follow-up, respectively. The corresponding proportion was 82.0% (524/639), 49.9% (174/349), and 38.8% (47/121) in the adolescent subcohort.

Conclusions

Our study cohort is one of the largest cohorts of patients with bariatric procedures in the United States. Patients are geographically and demographically diverse, which improves the generalizability of the research findings and allows examination of treatment effect heterogeneity. Ongoing and planned investigations will provide real-world evidence on the long-term benefits and risks of these most commonly used bariatric procedures in current clinical practice.

Physician Service Attribution Methods for Examining Provision of Low-Value Care

Objectives:

There has been significant research on provider attribution for quality and cost. Low-value care is an area of heightened focus, with little of the focus being on measurement; a key methodological decision is how to attribute delivered services and procedures. We illustrate the difference in relative and absolute physician- and panel-attributed services and procedures using overuse in cervical cancer screening.

Study Design:

A retrospective, cross-sectional study in an integrated health care system.

Methods:

We used 2013 physician-level data from Group Health Cooperative to calculate two utilization attributions: (1) panel attribution with the procedure assigned to the physician’s predetermined panel, regardless of who performed the procedure; and (2) physician attribution with the procedure assigned to the performing physician. We calculated the percentage of low-value cervical cancer screening tests and ranked physicians within the clinic using the two utilization attribution methods.

Results:

The percentage of low-value cervical cancer screening varied substantially between physician and panel attributions. Across the whole delivery system, median panel- and physician-attributed percentages were 15 percent and 10 percent, respectively. Among sampled clinics, panel-attributed percentages ranged between 10 percent and 17 percent, and physician-attributed percentages ranged between 9 percent and 13 percent. Within a clinic, median panel-attributed screening percentage was 17 percent (range 0 percent–27 percent) and physician-attributed percentage was 11 percent (range 0 percent–24 percent); physician rank varied by attribution method.

Conclusions:

The attribution method is an important methodological decision when developing low-value care measures since measures may ultimately have an impact on national benchmarking and quality scores. Cross-organizational dialogue and transparency in low-value care measurement will become increasingly important for all stakeholders.

Primary Care Clinicians' Perspectives on Reducing Low-Value Care in an Integrated Delivery System

CONTEXT

Perceptions about low-value care (eg, medical tests and procedures that may be unnecessary and/or harmful) among clinicians with capitated salaries are unknown.

OBJECTIVE

Explore clinicians' perceived use of and responsibility for reducing low-value care by focusing on barriers to use, awareness of the Choosing Wisely campaign, and response to reports of peer-comparison resource use and practice patterns.

METHODS

Electronic, cross-sectional survey, distributed in 2013, to 304 salaried primary care physicians and physician assistants at Group Health Cooperative.

MAIN OUTCOME MEASURES

Attitudes, awareness, and barriers of low-value care strategies and initiatives.

RESULTS

A total of 189 clinicians responded (62% response rate). More than 90% believe cost is important to various stakeholders and believe it is fair to ask clinicians to be cost-conscious. Most found peer-comparison resource-use reports useful for understanding practice patterns and prompting peer discussions. Two-thirds of clinicians were aware of the Choosing Wisely campaign; among them, 97% considered it a legitimate information source. Although 88% reported being comfortable discussing low-value care with patients, 80% reported they would order tests or procedures when a patient insisted. As key barriers in reducing low-value care, clinicians identified time constraints (45%), overcoming patient preferences/values (44%), community standards (43%), fear of patients' dissatisfaction (41%), patients' knowledge about the harms of low-value care (38%), and availability of tools to support shared decision making (37%).

CONCLUSIONS

Salaried clinicians are aware of rising health care costs and want to be stewards of limited health care resources. Evidence-based initiatives such as the Choosing Wisely campaign may help motivate clinicians to be conscientious stewards of limited health care resources.

The HMO Research Network Virtual Data Warehouse: A Public Data Model to Support Collaboration

The HMO Research Network (HMORN) Virtual Data Warehouse (VDW) is a public, non-proprietary, research-focused data model implemented at 17 health care systems across the United States. The HMORN has created a governance structure and specified policies concerning the VDW's content, development, implementation, and quality assurance. Data extracted from the VDW have been used by thousands of studies published in peer-reviewed journal articles. Advances in software supporting care delivery and claims processing and the availability of new data sources have greatly expanded the data available for research, but substantially increased the complexity of data management. The VDW data model incorporates software and data advances to ensure that comprehensive, up-to-date data of known quality are available for research. VDW governance works to accommodate new data and system complexities. This article highlights the HMORN VDW data model, its governance principles, data content, and quality assurance procedures. Our goal is to share the VDW data model and its operations to those wishing to implement a distributed interoperable health care data system.

Managing personal health information in distributed research network environments

BACKGROUND

Studying rare outcomes, new interventions and diverse populations often requires collaborations across multiple health research partners. However, transferring healthcare research data from one institution to another can increase the risk of data privacy and security breaches.

METHODS

A working group of multi-site research programmers evaluated the need for tools to support data security and data privacy. The group determined that data privacy support tools should: 1) allow for a range of allowable Protected Health Information (PHI); 2) clearly identify what type of data should be protected under the Health Insurance Portability and Accountability Act (HIPAA); and 3) help analysts identify which protected health information data elements are allowable in a given project and how they should be protected during data transfer. Based on these requirements we developed two performance support tools to support data programmers and site analysts in exchanging research data.

RESULTS

The first tool, a workplan template, guides the lead programmer through effectively communicating the details of multi-site programming, including how to run the program, what output the program will create, and whether the output is expected to contain protected health information. The second performance support tool is a checklist that site analysts can use to ensure that multi-site program output conforms to expectations and does not contain protected health information beyond what is allowed under the multi-site research agreements.

CONCLUSIONS

Together the two tools create a formal multi-site programming workflow designed to reduce the chance of accidental PHI disclosure.

Managing protected health information in distributed research network environments: automated review to facilitate collaboration

Background

Multi-site health sciences research is becoming more common, as it enables investigation of rare outcomes and diseases and new healthcare innovations. Multi-site research usually involves the transfer of large amounts of research data between collaborators, which increases the potential for accidental disclosures of protected health information (PHI). Standard protocols for preventing release of PHI are extremely vulnerable to human error, particularly when the shared data sets are large.

Methods

To address this problem, we developed an automated program (SAS macro) to identify possible PHI in research data before it is transferred between research sites. The macro reviews all data in a designated directory to identify suspicious variable names and data patterns. The macro looks for variables that may contain personal identifiers such as medical record numbers and social security numbers. In addition, the macro identifies dates and numbers that may identify people who belong to small groups, who may be identifiable even in the absences of traditional identifiers.

Results

Evaluation of the macro on 100 sample research data sets indicated a recall of 0.98 and precision of 0.81.

Conclusions

When implemented consistently, the macro has the potential to streamline the PHI review process and significantly reduce accidental PHI disclosures.

Validity of eight integrated healthcare delivery organizations' administrative clinical data to capture breast cancer chemotherapy exposure

BACKGROUND

Cancer Research Network (CRN) sites use administrative data to populate their Virtual Data Warehouse (VDW). However, information on VDW chemotherapy data validity is limited. The purpose of this study was to assess the validity of VDW chemotherapy data.

METHODS

This was a retrospective cohort study of women ≥18 years with incident, invasive breast cancer diagnosed between January 1999 and December 2007. Pharmacy and procedure chemotherapy data were extracted from each site's VDW. Random samples of 50 patients stratified on trastuzumab, anthracyclines, and no chemotherapy exposure was selected from each site for detailed chart abstraction. Weighted sensitivities and specificities of VDW compared with abstracted data were calculated. Cumulative doses calculated from VDW data were compared with doses obtained from the medical chart review.

RESULTS

The cohort included 13,497 patients with 6,456 (48%) chart review eligible. Patients in the sample (N = 400) had a mean age of 65 years. Trastuzumab, anthracycline, and other chemotherapy weighted sensitivities were 95%, 97%, and 100%, respectively; specificities were 99%, 99%, and 93%, respectively; positive predictive values were 96%, 99%, and 55%, respectively; and negative predictive values were 99%, 96%, and 100%. Trastuzumab and anthracyclines VDW mean doses were 873 and 386 mg, respectively, whereas abstracted mean doses were 1,734 and 369 mgs, respectively (R(2) = 0.14, P < 0.01 and R(2) = 0.05, P = 0.03, respectively).

CONCLUSIONS

Sensitivities and specificities for CRN chemotherapy VDW data were high and dosages were correlated with chart information.

IMPACT

The findings support the use of CRN data in evaluating chemotherapy exposures and related outcomes.

Building a virtual cancer research organization

BACKGROUND

The Cancer Research Network (CRN) comprises the National Cancer Institute and 11 nonprofit research centers affiliated with integrated health care delivery systems. The CRN, a public/private partnership, fosters multisite collaborative research on cancer prevention, screening, treatment, survival, and palliation in diverse populations.

METHODS

The CRN's success hinges on producing innovative cancer research that likely would not have been developed by scientists working individually, and then translating those findings into clinical practice within multiple population laboratories. The CRN is a collaborative virtual research organization characterized by user-defined sharing among scientists and health care providers of data files as well as direct access to researchers, computers, software, data, research participants, and other resources. The CRN's research management Web site fosters a high-functioning virtual scientific community by publishing standardized data definitions, file specifications, and computer programs to support merging and analyzing data from multiple health care systems.

RESULTS

Seven major types of standardized data files developed to date include demographics, health plan eligibility, tumor registry, inpatient and ambulatory utilization, medication dispensing, laboratory tests, and imaging procedures; more will follow. Data standardization avoids rework, increases multisite data integrity, increases data security, generates shorter times from initial proposal concept to submission, and stimulates more frequent collaborations among scientists across multiple institutions.

CONCLUSIONS

The CRN research management Web site and associated standardized data files and procedures represent a quasi-public resource, and the CRN stands ready to collaborate with researchers from outside institutions in developing and conducting innovative public domain research.

Efficacy of Prophylactic Mastectomy in Women With Unilateral Breast Cancer: A Cancer Research Network Project

Purpose

We investigated the efficacy of contralateral prophylactic mastectomy (CPM) in reducing contralateral breast cancer incidence and breast cancer mortality among women who have already been diagnosed with breast cancer.

Methods

This retrospective cohort study comprised approximately 50,000 women who were diagnosed with unilateral breast cancer during 1979 to 1999. Using computerized data confirmed by chart review, we identified 1,072 women (1.9%) who had CPM. We obtained covariate information for these women and for a sample of 317 women who did not undergo CPM.

Results

The median time from initial breast cancer diagnosis to the end of follow-up was 5.7 years. Contralateral breast cancer developed in 0.5% of women with CPM, metastatic disease developed in 10.5%, and subsequent breast cancer developed in 12.4%; 8.1% died from breast cancer. Contralateral breast cancer developed in 2.7% of women without CPM, and 11.7% died of breast cancer. After adjustment for initial breast cancer characteristics, treatment, and breast cancer risk factors, the hazard ratio (HR) for the occurrence of contralateral breast cancer after CPM was 0.03 (95% CI, 0.006 to 0.13). After adjustment for breast cancer characteristics and treatment, the HRs for the relationship of CPM with death from breast cancer, with death from other causes, and with all-cause mortality were 0.57 (95% CI, 0.45 to 0.72), 0.78 (95% CI, 0.57 to 1.06), and 0.60 (95% CI, 0.50 to 0.72), respectively.

Conclusion

CPM seems to protect against the development of contralateral breast cancer, and although women who underwent CPM had relatively low all-cause mortality, CPM also was associated with decreased breast cancer mortality.

Outcome measures across program sites for postsecondary supported education programs

This article briefly describes three supported education programs and examines outcomes for each. The program settings were a mental health center, a clubhouse, and a community college. Students (n = 124) were followed for five semesters to assess program outcomes. Although this study did not statistically control for variations in services among sites, each site adhered to the principles and practice of supported education as a specialized intervention. Differences among sites in student demographics, education and employment outcomes, satisfaction with school, job/education fit, satisfaction with life, and self-esteem are reported. Although there were variations in outcomes among sites, few signifcant differences were found.