Asymptomatic Veterans Research Articles

Long-term care facility employee infection prevention adherence and prevention of COVID-19 outbreaks in a high-incidence area

Background: Long-term care facility (LTCF) employees pose potential risk for COVID-19 outbreaks. Association between employee infection prevention (IP) adherence with facility COVID-19 outbreaks remains a knowledge gap. Methods: From April through December 2020, prior to COVID-19 vaccination, we tested asymptomatic Veterans’ Affairs (VA) community living center (CLC) residents twice weekly and employees monthly, which increased to weekly with known exposure, for SARS-CoV-2 via nasopharyngeal PCR. Employees voluntarily completed multiple choice questionnaires assessing self-reported IP adherence at and outside work. Surveys were longitudinally administered in April, June, July, and October 2020. Changes in paired employee responses for each period were analyzed using the McNemar test. We obtained COVID-19 community rates from surrounding Davidson and Rutherford counties from the Tennessee Department of Health public data set. CLC resident COVID-19 cases were obtained from VA IP data. Incidence rate and number of positive tests were calculated. Results: Between April and December 2020, 444 employees completed at least 1 survey; 177 completed surveys in both April and June, 179 completed surveys in both June and July, and 140 completed surveys in both July and October (Fig. 1). Across periods, employee surveys demonstrated an increase in masking at work and outside work between April and June (63% to 95% [P < .01] and 36% to 63% [P < .01], respectively), and June to July (95% to 99% [P < .05] and 71% to 84% [P < .01], respectively) that were both maintained between July and October (Fig. 2). Distancing at work and limiting social contacts outside work significantly decreased from April to June but increased in subsequent periods, although not significantly. COVID-19 community incidence peaked in July and again in December, but CLC resident COVID-19 cases peaked in August, declined, and remained low through December (Fig. 3). Discussion: Wearing a mask at work, which was mandatory, increased, and voluntary employee masking outside work also increased. CLC COVID-19 cases mirrored community increases in July and August; however, community cases increased again later in 2020 while CLC cases remained low. Employees reporting distancing at work and limiting social contacts outside work decreased preceding the initial rise in CLC cases but increased and remained high after July. Conclusions: These data from the pre–COVID-19 vaccination era suggest that widespread, increased support for and emphasis on LTCF IP adherence, especially masking, may have effectively prevented COVID-19 outbreaks in the vulnerable LTCF population.Funding: NoneDisclosures: None

Longitudinal assessment of colonoscopy adverse events in the prospective Cooperative Studies Program no. 380 colorectal cancer screening and surveillance cohort

Data are limited regarding colonoscopy risk during long-term, programmatic colorectal cancer screening and follow-up. We aimed to describe adverse events during follow-up in a colonoscopy screening program after the baseline examination and examine factors associated with increased risk. Cooperative Studies Program no. 380 includes 3121 asymptomatic veterans aged 50 to 75 years who underwent screening colonoscopy between 1994 and 1997. Periprocedure adverse events requiring significant intervention were defined as major events (other events were minor) and were tracked during follow-up for at least 10 years. Multivariable odds ratios (ORs) were calculated for factors associated with risk of follow-up adverse events. Of 3727 follow-up examinations in 1983 participants, adverse events occurred in 105 examinations (2.8%) in 93 individuals, including 22 major and 87 minor events (examinations may have had >1 event). Incidence of major events (per 1000 examinations) remained relatively stable over time, with 6.1 events at examination 2, 4.8 at examination 3, and 7.2 at examination 4. Examinations with major events included 1 perforation, 3 GI bleeds requiring intervention, and 17 cardiopulmonary events. History of prior colonoscopic adverse events was associated with increased risk of events (major or minor) during follow-up (OR, 2.7; 95% confidence interval, 1.6-4.6). Long-term programmatic screening and surveillance was safe, as major events were rare during follow-up. However, serious cardiopulmonary events were the most common major events. These results highlight the need for detailed assessments of comorbid conditions during routine clinical practice, which could help inform individual decisions regarding the utility of ongoing colonoscopy follow-up.

Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance

Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous histology or high-grade dysplasia, or colorectal cancer [CRC]) and assessed whether baseline colonoscopy findings were associated with long-term outcomes. We collected data from the Department of Veterans Affairs Cooperative Studies Program Study on 3121 asymptomatic veterans (50-75 years old) who underwent a screening colonoscopy from 1994 through 1997 at 13 medical centers and were then followed for 10 years or until death. We included 1915 subjects with at least 1 surveillance colonoscopy and estimated cumulative incidence of advanced neoplasia by Kaplan-Meier curves. We then fit a longitudinal joint model to estimate risk of advanced neoplasia at each subsequent examination after baseline, adjusting for multiple colonoscopies within individuals. Through 10 years of follow-up, there were 146 individuals among all baseline colonoscopy groups found to have at least 1 incident advanced neoplasia. The cumulative 10-year incidence of advanced neoplasia was highest among those with baseline CRC (43.7%; 95% CI 13.0%-74.4%), followed by those with baseline advanced adenoma (AA) (21.9%; 95% CI 15.7-28.1). The cumulative 10-year incidence of advanced neoplasia was 6.3% (95% CI 4.1%-8.5%) and 4.1% (95% CI 2.7%-5.4%) for baseline 1 to 2 small adenomas (<1cm, and without villous histology or high-grade dysplasia) and no neoplasia, respectively (log-rank P= .10). After adjusting for prior surveillance, the risk of advanced neoplasia at each subsequent examination was not significantly increased in veterans with 1 or 2 small adenomas at baseline (odds ratio 0.96; 95% CI 0.67-1.41) compared with veterans with no baseline neoplasia. Baseline screening colonoscopy findings associate with advanced neoplasia within 10 years. Individuals with only 1 or 2 small adenomas at baseline have a low risk of advanced neoplasia over 10 years. Alternative surveillance strategies, could be considered for these individuals.

Characterization of temporal relationships of comorbidities developed following cancer diagnoses in veterans.

e18049 Background: Understanding patient trajectories and common sequences of comorbidity accrual among those newly diagnosed with cancer is critical for precision approaches to care and prevention. The Veterans Affairs (VA) Cooperative Studies Program (CSP) #380 cohort includes 3,121 healthy asymptomatic veterans who underwent screening colonoscopy and were followed for at least ten years. The current analysis leverages computational approaches to characterize the temporal relationships of diagnoses in CSP #380 participants following diagnosis of colorectal or other cancers. Methods: Patients enrolled in CSP #380 with at least 5 years of linked electronic health record data from the VA Corporate Data Warehouse (October 1999-December 2015) were included. Cancer diagnoses and their most common subsequent new diagnoses were identified per patient by the first instance of each three-digit ICD-9 diagnosis affecting at least 50 patients. Pairwise chronological relative risks (RR) between subsequent diagnoses were represented as a directed network graph, which maps the probability of developing a diagnosis following a prior diagnosis. Results: A total of 2,210 patients were included. The most common cancer diagnoses were prostate (436), thoracic (169), bladder (120), colon (72), and kidney cancers (65). Most first diagnoses following a cancer diagnosis were related to progressive cancer or acute/subacute treatment toxicity. For prostate cancer, comorbidities with greatest RR were carcinoma in situ (RR 6.85), unspecified (NOS) metastases (2.75), and urethral stricture (2.53). For lung cancer, they were metastases of respiratory and digestive sites (12.24), lymph nodes (6.47), and NOS (5.68), pneumothorax and air leak (4.16), and convalescence and palliative care (3.07). In bladder cancer, they were carcinoma in situ (9.00), cystitis (6.78), kidney or other urinary cancer (6.19), attention to artificial openings (3.40), and urethral stricture (2.78). These and other results were visualized with network graphs. Conclusions: Computational techniques can identify and visualize future health concerns following cancer diagnoses. In this cohort of initially healthy and asymptomatic veterans on a prospective screening colonoscopy study, most subsequent diagnoses were related to cancer or toxicities of therapy, as might be expected in an aging cohort. Future work may focus on streamlining in-clinic identification of potential high likelihood comorbidities.

Abstract 16852: The Role of Repeat Stress Radionuclide Myocardial Perfusion Imaging for New or Progressive Cardiovascular Symptoms

Background: The appropriateness use criteria (AUC) offers guidance to assist with the appropriate use of cardiac imaging. The recent AUC consensus is that follow-up radionuclide myocardial perfusion imaging (MPI) within 2-years of a normal MPI is rarely appropriate in asymptomatic patients or in those with stable symptoms. The utility of repeat testing in a patient with new or progressive symptoms has not been studied. Methods: After IRB approval, records from veterans who underwent multiple MPI stress testing within 2-years of a negative MPI, between 2013 and 2016, at our VA Medical Center were accessed and variables of interest collected. Descriptive analysis as well as direct comparison by means of χ2 for dichotomous variables was conducted. Results: A total of 318 male veterans underwent repeat MPI within 2-years of a normal MPI. The median age was 65 [IQR, 59-70]. Among this group, repeat testing for new or progressive symptoms was done in 206 veterans (65%), compared to 112 (35%) veterans without symptoms. 50 cases had reversible ischemia on repeat MPI. Of these, 37 (18%) were symptomatic. Among asymptomatic veterans with a positive repeat MPI, 3 out of the 11 (27%) were noted to have obstructive coronary artery disease (CAD) on coronary angiogram. In contrast, 24 out of 37 veterans with symptoms underwent coronary angiogram, with 15 (40.6%) found to have obstructive CAD. Overall, 2.6% of asymptomatic veterans who underwent repeat MPI had obstructive CAD on coronary angiogram, compared to 7.2% of veterans who had repeat testing for new or progressive symptoms. Comparison of angiogram findings for abnormal MPIs based on the presence of symptoms on presentation did not reach statistical significance (p=0.053). Conclusion: Among asymptomatic veterans who underwent repeat MPI, &lt; 3% of veterans had obstructive CAD. These findings support the AUC’s position that for asymptomatic patients, repeat MPI within 2-years of a normal study is rarely appropriate. However, among veterans with symptoms, 7 % were found to have obstructive CAD, but the difference between asymptomatic and symptomatic patients did not reach statistical significance. In the setting of symptoms, a negative MPI within 2-years is possibly a marker of low risk for obstructive CAD.

Inspiratory airflow dynamics during sleep in veterans with Gulf War illness: a controlled study

To determine whether veterans with Gulf War Illness (GWI) are distinguished by sleep-disordered breathing, we compared inspiratory airflow dynamics during sleep between veterans with GWI and asymptomatic veterans of the first Gulf War. We recruited 18 male veterans with GWI and 11 asymptomatic male veterans of the first Gulf War by advertisement. The two samples were matched for age and body mass index. Each participant underwent a first full-night polysomnogram (PSG) while sleeping supine using standard clinical monitoring of sleep and breathing. A second PSG was performed measuring airflow with a pneumotachograph in series with a nasal mask and respiratory effort with a supraglottic pressure (Psg) catheter to assess the presence of inspiratory airflow limitation during supine N2 sleep. We determined the prevalence of flow-limited breaths by sampling continuous N2 sleep and plotting inspiratory flow against Psg for each breath in the sample. We expressed the prevalence of flow-limited breaths as their percentage in the sample. Compared to controls, veterans with GWI had an increased frequency of arousals related to apneas, hypopneas, and mild inspiratory airflow limitation. During supine N2 sleep, veterans with GWI had 96 ± 5% (mean ± SD) of their breaths flow-limited while controls had 36 ± 25% of their breaths flow limited (p < 0.0001). Veterans with GWI experience sleep-disordered breathing that may distinguish them from asymptomatic veterans of the first Gulf War.

Basal cerebral glucose distribution in long-term post-traumatic stress disorder

The purpose of this investigation was to study basal cerebral glucose absorption patterns associated to long-term post-traumatic stress disorder. Fluorodeoxyglucose positron emission tomography (FDG-PET) and statistic parametric mapping (SPM) were used to compare regional cerebral glucose absorption between 15 war veterans (Hispanic men, aged 39–41 (M = 39.5, SD = 0.84)) diagnosed with post-traumatic stress disorder (PTSD) based on DSM-IV criteria, and a matching control group of six asymptomatic veterans. This study was conducted 20 years after the traumatic events. PTSD patients presented relatively diminished activity (P<0.005) in: cingulate gyri, precuneus, insula, hippocampus; frontal, pre-frontal and post-central regions; lingual, calcarine, occipital medial and superior gyri, and verbal and paraverbal areas. Relativeley augmented activity (P<0.005) was observed in PTSD patients in: fusiform, temporal superior, medial, and inferior gyri; occipital medial, inferior and lingual gyri; precuneus, and cerebellum. The amygdala and the thalamus showed normal metabolic activity. Various brain regions that showed diminished activity (limbic, frontal and prefrontal cortex, multimodal parieto-occipital areas and verbal and paraverbal areas) have evolved lately, and sub-serve highly complex cognitive and behavioural functions. Metabolic activity patterns are comparable to those observed in personality disorders of the borderline type.

Chemical Sensitivity in Symptomatic Cambodia Veterans

Following their participation in a United Nations peacekeeping operation in Cambodia (1992-1993), Dutch veterans complained of symptoms similar to those reported by Gulf War veterans. The authors conducted a matched case-control study to evaluate 76 symptomatic and 32 matched asymptomatic Cambodia veterans on the basis of data collected by postal questionnaire. The number of symptomatic veterans who reported having used insect repellants that contained N,N,-diethyl-meta-toluamide (DEET) during the mission in Cambodia was significantly higher, compared with asymptomatic veterans. The percentage of veterans who reported feeling ill following brief exposures to chemicals such as paint or pesticides was equal in both groups, but the percentage was low compared with the results of other studies of Multiple Chemical Sensitivity Syndrome. The current study was limited by self-report and time delay (potential recall bias) between deployment to Cambodia and the time of survey. Nevertheless, the study results did not support the hypothesis that symptoms in the total group of Cambodia veterans could be related to Multiple Chemical Sensitivity Syndrome.

Efficacy of screening flexible sigmoidoscopy for colorectal neoplasia in asymptomatic subjects

purpose: Although flexible sigmoidoscopy is recommended in patients over age 40 to complement fecal occult blood screening for colorectal neoplasia, the yield of this procedure in asymptomatic, average-risk subjects has varied between studies. In addition, the efficacy of flexible sigmoidoscopy in detecting early curable carcinoma has been the subject of debate. We therefore undertook this study to assess the efficacy, safety, and cost of the procedure for early detection of colorectal neoplasia in asymptomatic subjects. patients and methods: Flexible sigmoidoscopy with a 60-cm scope was performed in 412 asymptomatic veterans (mean age, 63.2 years). Subjects with positive fecal occult blood and those at increased risk for colorectal neoplasia were excluded. Costs were estimated on the basis of Medicare payments. results: A mean length of 56.1 cm of sigmoid and descending solon was examined. A total of 132 polyps were detected in 93 subjects (22.6%). Thirty-five percent of the polyps were located at a distance of greater than 30 cm from the anal verge. Of 122 polyps removed, 26% were 1 cm in size or larger. A total of 77 polyps (63%) were adenomas, and six polyps (5%) were carcinomas. Of the six carcinomas detected (two carcinoma in situ, one Astler Coller stage A, two stage B1, and one stage C1), five were in a localized stage and thus potentially curable. The cost of detecting each potentially curable carcinoma was $47.174. No complications from flexible sigmoidoscopy were noted. conclusion: In conclusion, 60-cm flexible sigmoidoscopy is a safe, high-yield procedure for the initial screening of colorectal neoplasia in asymptomatic, average-risk subjects over the age of 50. Because the carcinomas detected were still in an early stage, such screening may improve survival.