Assembling and validating data from multiple sources to study care for Veterans with bladder cancer

Summary of Veterans Health Administration Cancer Data Sources

Objectives

The Veterans Health Administration (VHA) is a leader in generating transformational research across the cancer care continuum. Given the extensive body of cancer-related literature utilizing VHA data, our objectives are to: (1) describe the VHA data sources available for conducting cancer-related research, and (2) discuss examples of published cancer research using each data source.

Methods

We identified commonly used data sources within the VHA and reviewed previously published cancer-related research that utilized these data sources. In addition, we reviewed VHA clinical and health services research web pages and consulted with a multidisciplinary group of cancer researchers that included hematologist/oncologists, health services researchers, and epidemiologists.

Results

Commonly used VHA cancer data sources include the Veterans Affairs (VA) Cancer Registry System, the VA Central Cancer Registry (VACCR), the Corporate Data Warehouse (CDW)-Oncology Raw Domain (subset of data within the CDW), and the VA Cancer Care Cube (Cube). While no reference standard exists for cancer case ascertainment, the VACCR provides a systematic approach to ensure the complete capture of clinical history, cancer diagnosis, and treatment. Like many population-based cancer registries, a significant time lag exists due to constrained resources, which may make it best suited for historical epidemiologic studies. The CDW-Oncology Raw Domain and the Cube contain national information on incident cancers which may be useful for case ascertainment and prospective recruitment; however, additional resources may be needed for data cleaning.

Conclusions

The VHA has a wealth of data sources available for cancer-related research. It is imperative that researchers recognize the advantages and disadvantages of each data source to ensure their research questions are addressed appropriately.

Ascertainment of Veterans With Metastatic Prostate Cancer in Electronic Health Records: Demonstrating the Case for Natural Language Processing

PURPOSE

Prostate cancer (PCa) is among the leading causes of cancer deaths. While localized PCa has a 5-year survival rate approaching 100%, this rate drops to 31% for metastatic prostate cancer (mPCa). Thus, timely identification of mPCa is a crucial step toward measuring and improving access to innovations that reduce PCa mortality. Yet, methods to identify patients diagnosed with mPCa remain elusive. Cancer registries provide detailed data at diagnosis but are not updated throughout treatment. This study reports on the development and validation of a natural language processing (NLP) algorithm deployed on oncology, urology, and radiology clinical notes to identify patients with a diagnosis or history of mPCa in the Department of Veterans Affairs.

PATIENTS AND METHODS

Using a broad set of diagnosis and histology codes, the Veterans Affairs Corporate Data Warehouse was queried to identify all Veterans with PCa. An NLP algorithm was developed to identify patients with any history or progression of mPCa. The NLP algorithm was prototyped and developed iteratively using patient notes, grouped into development, training, and validation subsets.

RESULTS

A total of 1,144,610 Veterans were diagnosed with PCa between January 2000 and October 2020, among which 76,082 (6.6%) were identified by NLP as having mPCa at some point during their care. The NLP system performed with a specificity of 0.979 and sensitivity of 0.919.

CONCLUSION

Clinical documentation of mPCa is highly reliable. NLP can be leveraged to improve PCa data. When compared to other methods, NLP identified a significantly greater number of patients. NLP can be used to augment cancer registry data, facilitate research inquiries, and identify patients who may benefit from innovations in mPCa treatment.

The impact of low- versus high-intensity surveillance cystoscopy on surgical care and cancer outcomes in patients with high-risk non-muscle-invasive bladder cancer (NMIBC)

Purpose

To assess the association of low- vs. guideline-recommended high-intensity cystoscopic surveillance with outcomes among patients with high-risk non-muscle invasive bladder cancer (NMIBC).

Materials & methods

A retrospective cohort study of Veterans Affairs patients diagnosed with high-risk NMIBC between 2005 and 2011 with follow-up through 2014. Patients were categorized by number of surveillance cystoscopies over two years following diagnosis: low- (1–5) vs. high-intensity (6 or more) surveillance. Propensity score adjusted regression models were used to assess the association of low-intensity cystoscopic surveillance with frequency of transurethral resections, and risk of progression to invasive disease and bladder cancer death.

Results

Among 1,542 patients, 520 (33.7%) underwent low-intensity cystoscopic surveillance. Patients undergoing low-intensity surveillance had fewer transurethral resections (37 vs. 99 per 100 person-years; p<0.001). Risk of death from bladder cancer did not differ significantly by low (cumulative incidence [CIn] 8.4% [95% CI 6.5–10.9) at 5 years) vs. high-intensity surveillance (CIn 9.1% [95% CI 7.4–11.2) at 5 years, p = 0.61). Low vs. high-intensity surveillance was not associated with increased risk of bladder cancer death among patients with Ta (CIn 5.7% vs. 8.2% at 5 years p = 0.24) or T1 disease at diagnosis (CIn 10.2% vs. 9.1% at 5 years, p = 0.58). Among patients with Ta disease, low-intensity surveillance was associated with decreased risk of progression to invasive disease (T1 or T2) or bladder cancer death (CIn 19.3% vs. 31.3% at 5 years, p = 0.002).

Conclusions

Patients with high-risk NMIBC undergoing low- vs. high-intensity cystoscopic surveillance underwent fewer transurethral resections, but did not experience an increased risk of progression or bladder cancer death. These findings provide a strong rationale for a clinical trial to determine whether low-intensity surveillance is comparable to high-intensity surveillance for cancer control in high-risk NMIBC.

National trends in the treatment of urinary tract infections among Veterans' Affairs Community Living Center residents

OBJECTIVE

To describe urinary tract infection (UTI) treatment among Veterans' Affairs (VA) Community Living Centers (CLCs) nationally and to assess related trends in antibiotic use.

DESIGN

Descriptive study.

SETTING AND PARTICIPANTS

All UTI episodes treated from 2013 through 2017 among residents in 110 VA CLCs. UTI episodes required collection of a urine culture, antibiotic treatment, and a UTI diagnosis code. UTI episodes were stratified into culture-positive and culture-negative episodes.

METHODS

Frequency and rate of antibiotic use were assessed for all UTI episodes overall and were stratified by culture-positive and culture-negative episodes. Joinpoint software was used for regression analyses of trends over time.

RESULTS

We identified 28,247 UTI episodes in 14,983 Veterans. The average age of Veterans was 75.7 years, and 95.9% were male. Approximately half of UTI episodes (45.7%) were culture positive and 25.7% were culture negative. Escherichia coli was recovered in 34.1% of culture-positive UTI episodes, followed by Proteus mirabilis and Klebsiella spp, which were recovered in 24.5% and 17.4% of culture-positive UTI episodes, respectively. The rate of total antibiotic use in days of therapy (DOT) per 1,000 bed days decreased by 10.1% per year (95% CI, -13.6% to -6.5%) and fluoroquinolone use (ciprofloxacin or levofloxacin) decreased by 14.5% per year (95% CI, -20.6% to -7.8%) among UTI episodes overall. Similar reductions in rates of total antibiotic use and fluoroquinolone use were observed among culture-positive UTI episodes and among culture-negative UTI episodes.

CONCLUSION

Over a 5-year period, antibiotic use for UTIs significantly decreased among VA CLCs, as did use of fluoroquinolones. Antibiotic stewardship efforts across VA CLCs should be applauded, and these efforts should continue.

Overuse of Cystoscopic Surveillance Among Patients With Low-risk Non-Muscle-invasive Bladder Cancer - A National Study of Patient, Provider, and Facility Factors

OBJECTIVE

To understand cystoscopic surveillance practices among patients with low-risk non-muscle-invasive bladder cancer (NMIBC) within the Department of Veterans Affairs (VA).

METHODS

Using a validated natural language processing algorithm, we included patients newly diagnosed with low-risk (ie low-grade Ta) NMIBC from 2005 to 2011 in the VA. Patients were followed until cancer recurrence, death, last contact, or 2 years after diagnosis. Based on guidelines, surveillance overuse was defined as >1 cystoscopy if followed <1 year, >2 cystoscopies if followed 1 to <2 years, or >3 cystoscopies if followed for 2 years. We identified patient, provider, and facility factors associated with overuse using multilevel logistic regression.

RESULTS

Overuse occurred in 75% of patients (852/1135) - with an excess of 1846 more cystoscopies performed than recommended. Adjusting for 14 factors, overuse was associated with patient race (odds ratio [OR] 0.49, 95% confidence interval [CI]: 0.28, 0.85 unlisted race vs White), having 2 comorbidities (OR 1.60, 95% CI: 1.00, 2.55 vs no comorbidities), and earlier year of diagnosis (OR 2.50, 95% CI: 1.29, 4.83 for 2005 vs 2011, and OR 2.03, 95% CI: 1.11, 3.69 for 2006 vs 2011). On sensitivity analyses assuming all patients were diagnosed with multifocal or large low-grade tumors (ie, intermediate-risk), overuse would have still occurred in 45% of patients.

CONCLUSION

Overuse of cystoscopy among patients with low-risk NMIBC was common, raising concerns about bladder cancer surveillance cost and quality. However, few factors were associated with overuse. Further qualitative research is needed to identify other determinants of overuse not readily captured in administrative data.

The impact of frequent cystoscopy on surgical care and cancer outcomes among patients with low-risk, non-muscle-invasive bladder cancer

BACKGROUND

Surveillance recommendations for patients with low-risk, non-muscle-invasive bladder cancer (NMIBC) are based on limited evidence. The objective of this study was to add to the evidence by assessing outcomes after frequent versus recommended cystoscopic surveillance.

METHODS

This was a retrospective cohort study of patients diagnosed with low-risk (low-grade Ta (AJCC)) NMIBC from 2005 to 2011 with follow-up through 2014 from the Department of Veterans Affairs. Patients were classified as having undergone frequent versus recommended cystoscopic surveillance (>3 vs 1-3 cystoscopies in the first 2 years after diagnosis). By using propensity score-adjusted models, the authors estimated the impact of frequent cystoscopy on the number of transurethral resections, the number of resections without cancer in the specimen, and the risk of progression to muscle-invasive cancer or bladder cancer death.

RESULTS

Among 1042 patients, 798 (77%) had more frequent cystoscopy than recommended. In adjusted analyses, the frequent cystoscopy group had twice as many transurethral resections (55 vs 26 per 100 person-years; P < .001) and more than 3 times as many resections without cancer in the specimen (5.7 vs 1.6 per 100 person-years; P < .001). Frequent cystoscopy was not associated with time to progression or bladder cancer death (3% at 5 years in both groups; P = .990).

CONCLUSIONS

Frequent cystoscopy among patients with low-risk NMIBC was associated with twice as many transurethral resections and did not decrease the risk for bladder cancer progression or death, supporting current guidelines.

Extent of Risk-Aligned Surveillance for Cancer Recurrence Among Patients With Early-Stage Bladder Cancer

IMPORTANCE

Cancer care guidelines recommend aligning surveillance frequency with underlying cancer risk, ie, more frequent surveillance for patients at high vs low risk of cancer recurrence.

OBJECTIVE

To assess the extent to which such risk-aligned surveillance is practiced within US Department of Veterans Affairs facilities by classifying surveillance patterns for low- vs high-risk patients with early-stage bladder cancer.

DESIGN SETTING AND PARTICIPANTS

US national retrospective cohort study of a population-based sample of patients diagnosed with low-risk or high-risk early-stage bladder between January 1, 2005, and December 31, 2011, with follow-up through December 31, 2014. Analyses were performed March 2017 to April 2018. The study included all Veterans Affairs facilities (n = 85) where both low-and high-risk patients were treated.

EXPOSURES

Low-risk vs high-risk cancer status, based on definitions from the European Association of Urology risk stratification guidelines and on data extracted from diagnostic pathology reports via validated natural language processing algorithms.

MAIN OUTCOMES AND MEASURES

Adjusted cystoscopy frequency for low-risk and high-risk patients for each facility, estimated using multilevel modeling.

RESULTS

The study included 1278 low-risk and 2115 high-risk patients (median [interquartile range] age, 77 [71-82] years; 99% [3368 of 3393] male). Across facilities, the adjusted frequency of surveillance cystoscopy ranged from 3.7 to 6.2 (mean, 4.8) procedures over 2 years per patient for low-risk patients and from 4.6 to 6.0 (mean, 5.4) procedures over 2 years per patient for high-risk patients. In 70 of 85 facilities, surveillance was performed at a comparable frequency for low- and high-risk patients, differing by less than 1 cystoscopy over 2 years. Surveillance frequency among high-risk patients statistically significantly exceeded surveillance among low-risk patients at only 4 facilities. Across all facilities, surveillance frequencies for low- vs high-risk patients were moderately strongly correlated (r = 0.52; P < .001).

CONCLUSIONS AND RELEVANCE

Patients with early-stage bladder cancer undergo cystoscopic surveillance at comparable frequencies regardless of risk. This finding highlights the need to understand barriers to risk-aligned surveillance with the goal of making it easier for clinicians to deliver it in routine practice.