Biomedical subjects

J A Davila

Publications and source records attributed to J A Davila.

5 recordsLinked to original sources

PubMed2007

GI Epidemiology: databases for epidemiological studies.

BACKGROUND: Large databases are being increasingly used for examining the epidemiology and outcomes of digestive and liver disorders. The complexity and rigor of the methods used to conduct these studies are often underestimated. AIMS: For the most commonly used databases, we provide a brief description of the contents, highlight strengths and weakness, and provide links for more detailed information. We also present a systematic approach to utilizing large databases for addressing research questions, highlighting commonly encountered study design issues, as well as strategies for resolving these issues. CONCLUSIONS: 1. Research using large databases requires the same essential skills needed to conduct research studies using other data sources. These include a rigorous study design, expertise in analytic methods, and relevant research questions. 2. The completeness and accuracy of information contained in the database must be assessed. Methods for improving the quality and completeness of this information should be considered. 3. Despite similarities among large databases, gaining insight and experience into the structure and content of each database is essential. Key points *Large databases can be a powerful source of information to examine the clinical epidemiology and outcomes of digestive and liver disorders. * Research using large databases requires the same essential skills needed to conduct research studies using other data sources. These include a rigorous study design, expertise in analytic methods, and relevant research questions. * The completeness and accuracy of information contained in the database must be assessed. Methods for improving the quality and completeness of this information should be considered. * Despite similarities among large databases, gaining insight and experience into the structure and content of each database is essential. * Examples of commonly used large databases are presented with a synopsis of information contained in the database, as well as strengths and limitations of using the database for research.

Databases as Topic↗

PubMed2006

The epidemiology of pancreatic cancer in the United States: changes below the surface.

BACKGROUND: Pancreatic cancer is the fourth leading cause of cancer death in the United States. AIM: To examine temporal changes in the incidence and survival of patients with pancreatic adenocarcinoma. METHODS: Using data from nine registries of the Surveillance, Epidemiology and End Results programme, age-adjusted incidence rates per 100 000 and survival rates were calculated for pancreatic cancer between 1977 and 2001. RESULTS: We identified 58 655 cases of pancreatic cancer. The age-adjusted incidence rate remained stable during the study period (11.3 in 1977-1981 and 10.9 in 1997-2001). Overall, men were 30% more affected than women (age-adjusted incidence rate of 13.0 in men and 9.8 in women). The age-adjusted incidence rates were almost 50% higher among Blacks (16.4) than Whites (10.8) and people of other races (9.8). Over time the proportions of patients with localized disease decreased from 12.3% to 7.4% and those with regional disease increased from 18.6% to 25.8%, while metastatic disease remained stable (52.5% vs. 49.8%). The 1-year relative survival increased from 15.2% in 1977-1981 to 21.6% in 1997-2001. CONCLUSIONS: The incidence of pancreatic cancer is stable. A shift from localized to regional disease was observed over time. The overall survival remains poor despite important improvements among patients with early stage disease.

Adenocarcinoma↗

PubMed2005

Increased use of low anterior resection for veterans with rectal cancer.

BACKGROUND: Two surgical procedures with curative intent are available to patients with rectal cancer: lower anterior resection and abdominoperineal resection; however, lower anterior resection may improve quality of life and functional status. AIM: To examine temporal changes in after lower anterior resection and abdominoperineal resection between 1989 and 2000. Potential factors associated with the use of lower anterior resection were evaluated. METHODS: Using national administrative data, we identified patients who received lower anterior resection or abdominoperineal resection. Logistic regression models examined the association between use of lower anterior resection and time period of surgical resection. RESULTS: A total of 5201 rectal cancer patients underwent resection. The use of lower anterior resection increased from 40.0% (1989-91) to 50.1% (1998-2000) paralleled by a corresponding decline in abdominoperineal resection (60.1 to 49.9%; P < 0.001). Patients who received surgery during 1992-94, 1995-97 and 1998-2000 were 6, 7 and 28% more likely to receive lower anterior resection, when compared with 1989-1991 after adjusting for demographic characteristics, co-morbidity and hospital surgical volume. Older age, lower co-morbidity score and lower hospital surgical volume were predictive of lower anterior resection. CONCLUSIONS: An increase in the use of lower anterior resection for rectal cancer was observed over time. This observed increase in use is not confined to high-volume hospitals.

Adult↗

PubMed2005

Diabetes increases the risk of hepatocellular carcinoma in the United States: a population based case control study.

BACKGROUND: Diabetes has been associated with an increased risk of hepatocellular carcinoma (HCC) in studies of referred patients. This is the first population based case control study in the USA to examine this association while adjusting for other major risk factors related to HCC. METHODS: We used the Surveillance Epidemiology and End-Results Program (SEER)-Medicare linked database to identify patients aged 65 years and older diagnosed with HCC and randomly selected non-cancer controls between 1994 and 1999. Only cases and controls with continuous Medicare enrollment for three years prior to the index date were examined. Inpatient and outpatient claims files were searched for diagnostic codes indicative of diabetes, hepatitis C virus (HCV), hepatitis B virus (HBV), alcoholic liver disease, and haemochromatosis. HCC patients without these conditions were categorised as idiopathic. Unadjusted and adjusted odds ratios were calculated in logistic regression analyses. RESULTS: We identified 2061 HCC patients and 6183 non-cancer controls. Compared with non-cancer controls, patients with HCC were male (66% v 36%) and non-White (34% v 18%). The proportion of HCC patients with diabetes (43%) was significantly greater than non-cancer controls (19%). In multiple logistic regression analyses that adjusted for demographics features and other HCC risk factors (HCV, HBV, alcoholic liver disease, and haemochromatosis), diabetes was associated with a threefold increase in the risk of HCC. In a subset of patients without these major risk factors, the adjusted odds ratio for diabetes declined but remained significant (adjusted odds ratio 2.87 (95% confidence interval 2.49-3.30)). A significant positive interaction between HCV and diabetes was detected (p<0.0001). Similar findings persisted in analyses restricted to diabetes recorded between two and three years prior to HCC diagnosis. CONCLUSIONS: Diabetes is associated with a 2-3-fold increase in the risk of HCC, regardless of the presence of other major HCC risk factors. Findings from this population based study suggest that diabetes is an independent risk factor for HCC.

Aged↗

PubMed2004

Outcomes in elderly patients following surgery for colorectal cancer in the veterans affairs health care system.

AIM: To compare 30-day and 5-year mortality in elderly vs. younger patients following surgical resection for colorectal cancer. METHODS: A cohort study of patients admitted to VA hospitals with a new diagnosis of colorectal cancer who underwent surgical resection between October 1990 and September 2000. Cumulative survival rates (30-day and 5-year) were calculated from Kaplan-Meier estimates and adjusted risks of death were estimated using Cox proportional hazards models. RESULTS: We identified 34,888 individuals with a new diagnosis of colorectal cancer between October 1990 and September 2000, of whom 22 633 (65%) underwent surgical resection. The 30-day mortality following resection for rectal and colon cancer, respectively, for patients <65 years was 2.1 and 2.8% compared with 4.9 and 5.6% for those > or =65 years. The 5-year cumulative survival for rectal and colon cancer for patients <65 years was 54.0 and 57.6% compared with 44.5 and 46.6% for those > or =65 years. In patients > or =65 years with rectal or colon cancer, after adjustment, 30-day mortality was 2 times greater and 5-year mortality was 1 times greater than in younger patients. CONCLUSIONS: Older age is an independent predictor of increased short-term and long-term mortality following surgery in patients with rectal and colon cancer.

Age Factors↗