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Gregory S Cooper

Publications and source records attributed to Gregory S Cooper.

31 records · Page 2Linked to original sources
PubMed2003

Prediction of outcome in acute lower-gastrointestinal haemorrhage based on an artificial neural network: internal and external validation of a predictive model.

BACKGROUND: Models based on artificial neural networks (ANN) are useful in predicting outcome of various disorders. There is currently no useful predictive model for risk assessment in acute lower-gastrointestinal haemorrhage. We investigated whether ANN models using information available during triage could predict clinical outcome in patients with this disorder. METHODS: ANN and multiple-logistic-regression (MLR) models were constructed from non-endoscopic data of patients admitted with acute lower-gastrointestinal haemorrhage. The performance of ANN in classifying patients into high-risk and low-risk groups was compared with that of another validated scoring system (BLEED), with the outcome variables recurrent bleeding, death, and therapeutic interventions for control of haemorrhage. The ANN models were trained with data from patients admitted to the primary institution during the first 12 months (n=120) and then internally validated with data from patients admitted to the same institution during the next 6 months (n=70). The ANN models were then externally validated and direct comparison made with MLR in patients admitted to an independent institution in another US state (n=142). FINDINGS: Clinical features were similar for training and validation groups. The predictive accuracy of ANN was significantly better than that of BLEED (predictive accuracy in internal validation group for death 87% vs 21%; for recurrent bleeding 89% vs 41%; and for intervention 96% vs 46%) and similar to MLR. During external validation, ANN performed well in predicting death (97%), recurrent bleeding (93%), and need for intervention (94%), and it was superior to MLR (70%, 73%, and 70%, respectively). INTERPRETATION: ANN can accurately predict the outcome for patients presenting with acute lower-gastrointestinal haemorrhage and may be generally useful for the risk stratification of these patients.

Acute Disease↗
PubMed2003

Effectiveness of open-access endoscopy in routine primary-care practice.

BACKGROUND: Direct referral of patients for endoscopic procedures without prior consultation (open-access endoscopy) has become commonplace. However, the effect of open-access endoscopy on the care of patients in routine clinical practice has not been studied. METHODS: The impact of open-access endoscopy was examined in 168 consecutive patients referred from 8 primary-care practices to our tertiary hospital-based endoscopy center. The effectiveness of open-access endoscopy was assessed by review of office medical records at the primary-care practice sites for a minimum follow-up period of 6 months. Outcome measures evaluated included postprocedure communication between primary-care physician and patient, primary-care physician adherence to postprocedure recommendations, and the need for subsequent diagnostic evaluation and/or consultation. RESULTS: The mean age of the 168 patients was 60 years; 56 (33%) underwent EGD and 112 (67%) had colonoscopy; 65% were from hospital-based practices and 35% from community practices. The indication(s) for 77% of the procedures met American Society for Gastrointestinal Endoscopy guidelines for the appropriate use of endoscopy. An office follow-up was noted for 82% of patients after the open-access procedure. Discussion of results was documented in 61% of the patient charts. Compliance with diagnostic and therapeutic recommendations was documented, respectively, in 75% and 90% of patient charts. A follow-up GI consultation was requested for only 7% of the patients. CONCLUSION: Open-access endoscopy in the primary-care setting is effective to the extent that subsequent GI consultations are rare and the level of compliance with endoscopist recommendations is high. However, documentation of communication of the results of endoscopy with the patient can be improved.

Aged↗
PubMed2003

Ability of Medicaid claims data to identify incident cases of breast cancer in the Ohio Medicaid population.

BACKGROUND: The use of Medicaid data to study cancer-related outcomes would be highly desirable. However, the accuracy of Medicaid claims data in the identification of incident cases of breast cancer is unknown. OBJECTIVES: (1) To estimate the sensitivity of Medicaid claims data for case ascertainment of breast cancer, and (2) to determine the positive predictive value (PPV) of diagnostic and procedure codes retrieved from Medicaid claims, using the Ohio Cancer Incidence Surveillance System (OCISS) as the gold standard. METHODS: The study used the linked OCISS and Medicaid enrollment files, 1997-1998 (n = 1,648). The claims search yielded 2,635 incident cases, of which 1,132 were also identified through the OCISS-Medicaid files. Sensitivity and PPV of Medicaid data were calculated in subgroups of the population. RESULTS: The overall sensitivity was 68.7 percent, but varied greatly across the subgroups of the population. It was lower among women enrolled in Medicaid only for part of the study year than those enrolled in Medicaid for 12 months of the study year (56.7 percent and 78.0 percent respectively, p < 0.0001), and lower among those who are dual Medicare-Medicaid eligible compared to those not participating in the Medicare program (63.1 percent and 78.6 percent respectively, p < 0.0001). The overall PPV was 43.0 percent, increasing up to 86.6 percent in the presence of procedure codes indicating the presence of mastectomy and lumpectomy, in addition to that of breast cancer diagnosis. CONCLUSIONS: The sensitivity of Medicaid claims for case ascertainment of breast cancer is somewhat low, but improves considerably when accounting for women enrolled in Medicaid for the entire duration of the study year. The PPV is poor due to a high rate of false positives. The higher PPV obtained in the presence of procedure codes, in addition to diagnosis codes, will help researchers to correctly identify incident cases of breast cancer using Medicaid claims data.

Adult↗
PubMed2002

Association of prediagnosis endoscopy with stage and survival in adenocarcinoma of the esophagus and gastric cardia.

BACKGROUND: Barrett esophagus, a consequence of chronic gastroesophageal reflux disease, is a premalignant condition for adenocarcinoma of the esophagus and, possibly, the gastric cardia. However, the actual use and clinical impact of upper gastrointestinal endoscopy in screening and surveillance for Barrett esophagus are unknown. METHODS: A cohort included 1633 patients with adenocarcinoma (777 esophagus, 856 cardia) who were 70 years or older. They were diagnosed between 1993 and 1996 and were identified from the Surveillance, Epidemiology and End Results program registry. All claims for upper endoscopy and a diagnosis of Barrett esophagus from 1991 through 1 year before diagnosis were identified from linked Medicare files. RESULTS: One or more upper endoscopies before diagnosis were performed in 9.7% of patients (13.0% esophagus, 6.8% cardia) and a diagnosis of Barrett esophagus was present in only 3.7% of patients. A shift toward earlier stage at diagnosis was observed in patients with previous endoscopy or Barrett diagnosis. For example, 62% of patients with esophageal and 49% of patients with cardia tumors who underwent previous endoscopy presented with in situ or local stage carcinoma, compared with 35% and 27% of other patients, respectively. Receipt of endoscopy was also associated with a reduced risk of death for esophageal adenocarcinoma (relative hazard 0.73, 95% confidence interval 0.57-0.93; P = 0.01), but not for adenocarcinoma of the cardia. CONCLUSIONS: Receipt of upper endoscopy at least 1 year before diagnosis of adenocarcinoma, which may reflect prediagnosis screening, was associated with an earlier tumor stage and improved survival. These data support the role of endoscopic screening and surveillance for Barrett esophagus and highlight the underdiagnosis of populations at risk.

Adenocarcinoma↗
PubMed2002

Use of Medicare claims data to measure county-level variation in breast carcinoma incidence and mammography rates.

BACKGROUND: National-level population-based data about breast carcinoma incidence and its association with screening mammography are currently not available. METHODS: Inpatient, hospital outpatient and physician/supplier Medicare claims were used to identify incident cases of breast carcinoma in women > or = 65 years from 1996 to 1997 and calculate county-level incidence rates. The 1994-1995 claims data were used to determine county-level rates of mammography, and determine the correlation with incidence. RESULTS: The median 2-year incidence rate for women > or = 65 was 979/100,000, and substantial variation in incidence between counties was observed. (i.e. 25th percentile 789/100,000, 75th percentile 1186/100,000). Two-year county-level mammography rates also varied among counties (i.e. 25th percentile 30.5%, 75th percentile 40.9%) and were higher in white women than in black women (median 36.8 and 26.3%, respectively). Counties with higher rates of mammography also had higher age-adjusted incidence rates. CONCLUSIONS: Medicare claims may provide an alternative source of population-based data, particularly for areas in which registry data are not readily available, or are of limited scope. The data highlight the geographic variation in incidence and screening rates that may be useful for targeted interventions, and also suggest that mammography remains in a growth phase.

Aged↗
PubMed2002

A prospective evaluation of outcome in patients referred for PEG placement.

BACKGROUND: PEG feeding is not recommended for short-term use because the 30-day mortality after PEG placement is substantial. The primary aim of this study was to prospectively identify factors predictive of survival in patients referred for PEG placement. METHODS: All patients for whom gastroenterology consultation was sought for feeding PEG placement were prospectively studied. Demographic data, Charlson comorbidity index, and functional status were recorded at entry. After PEG placement, patients were followed for up to 12 months. RESULTS: Of the 67 patients for whom consultation was requested, 58 were eligible for the study and 50 underwent PEG placement. The 7-day and 30-day mortality rates in the PEG placement group were 4% and 20%, respectively. In multivariate analysis, only the Charlson index > or =4 was associated with decreased survival time (relative hazard = 2.9: 95% CI [1.20, 7.21], p = 0.019). Median survival in patients with Charlson comorbidity index > or =4 was significantly shorter than that in patients with Charlson index < 4 (p = 0.013). CONCLUSIONS: A Charlson comorbidity index > or =4 was significantly associated with shorter patient survival after initial consultation. Careful consideration of predictive factors of survival may improve patient selection for feeding PEG placement.

Aged↗
PubMed2002

Correlation of EUS measurement with pathologic assessment of neoadjuvant therapy response in esophageal carcinoma.

BACKGROUND: EUS-measured reduction in tumor size after neoadjuvant therapy has previously been correlated with downstaging and improved survival in patients with esophageal cancer. The aim of this study was to determine whether tumor changes measured by EUS correspond to pathologically assessed chemoradiotherapy-induced tumor regression. METHODS: Forty-one patients with esophageal cancer treated with combined modality treatment were studied. After initial EUS, patients completed a cisplatin/carboplatinum, 5-fluorouracil, and radiotherapy regimen and underwent repeat EUS before resection. A positive response on EUS was defined as a 50% reduction in maximal tumor cross-sectional area. Chemoradiotherapy-induced tumor regression was assessed in resection specimens by using a previously defined pathologic scoring system based on the extent of tumor proliferation into adjacent fibrosis. RESULTS: Pathologic tumor regression was present in 23, indeterminate in 5, and minimal or absent in 13 patients. EUS measured a positive response in 20 of 23 (87%) patients with CRT-induced tumor regression and a negative response in 10 of 13 (77%) patients with absent tumor regression (p < 0.001). EUS had a positive predictive value of 80% for pathologic tumor regression. CONCLUSIONS: Measurement of tumor size by EUS is a reliable clinical method for assessing pathologic tumor regression before surgery.

Adult↗
PubMed2002

Patient tolerance and acceptance of unsedated ultrathin esophagoscopy.

BACKGROUND: Unsedated endoscopy has not gained wide acceptance in the United States. Factors that may predict tolerance and acceptance of unsedated endoscopy are ill defined. METHODS: Outpatients referred for standard EGD were recruited to undergo unsedated ultrathin esophagoscopy (UUE) with a new 3.1-mm battery-powered esophagoscope before sedated EGD. They rated preprocedure and postprocedure anxiety levels with the Profile of Mood States Tension/Anxiety subscale (POMS-SF T/A). They also rated symptoms and overall acceptability and listed procedural preference between EGD and UUE. Patients who refused UUE noted a reason for refusal and also completed the anxiety questionnaire. RESULTS: Fifty-two of 98 patients recruited agreed to participate, and underwent both UUE and EGD. Patients who refused UUE were significantly more anxious (mean anxiety score, 8.2 vs. 4.5, p < 0.005). Participants reported no significant difference between preprocedural (4.6 vs. 5.3) or postprocedural (3.5 vs. 2.6) anxiety for UUE versus standard EGD. After undergoing both procedures, only 46% stated they would prefer UUE to EGD in the future. Patients who chose the peroral approach were more likely to prefer UUE than those who chose the transnasal approach (58% vs. 23%, p = 0.02). CONCLUSIONS: Patient acceptance of unsedated endoscopy even with an ultrathin instrument is limited. Anxiety assessment by the POMS-SF T/A can identify patients willing to undergo UUE. Patients who choose transoral UUE may be more willing to repeat the procedure.

Adult↗
PubMed2002

Measuring breast, colorectal, and prostate cancer screening with medicare claims data.

BACKGROUND: Evaluating the use and effectiveness of cancer screening is an important component of cancer control programs. Medicare claims may be a useful source of data when screening older populations, but they are limited in terms of completeness and the ability to distinguish screening tests from those provided for diagnosis or surveillance. RESEARCH DESIGN: A review of the major screening modalities for breast, colorectal, and prostate cancer, Medicare's policies for covering these tests, and the procedure codes used to identify them in Medicare claims. RESULTS: Although Medicare's coverage has been extended to include screening mammography, colonoscopy, sigmoidoscopy, fecal occult blood tests, double-contrast barium enema, and prostate-specific antigen tests, providers have been slow to adopt the corresponding screening codes. CONCLUSION: Challenges persist in measuring screening use, and innovative approaches are required to distinguish screening tests from diagnostic and follow-up evaluations.

Aged↗
PubMed2002

Use of SEER-Medicare data for measuring cancer surgery.

BACKGROUND: The accuracy and completeness of the SEER-Medicare data for measuring cancer-related therapy have not been extensively evaluated. OBJECTIVES: To investigate the best method for measuring cancer-related surgery among patients in the SEER-Medicare database. SUBJECTS: A total of 149,970 incident cases of breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1991 and 1993.MEASURES The most invasive surgical procedure identified through Medicare's inpatient, physician, and hospital outpatient claims was compared with corresponding data from the SEER files. RESULTS: Agreement between the SEER and Medicare files was generally highest for resection and radical surgery (eg, kappa 0.70-0.90). While there was less agreement regarding no surgical therapy and biopsy individually, the concordance of the two sources in excluding cancer-directed surgery was high. Compared with inpatient data alone, using the combined inpatient, physician, and outpatient data increased concordance between SEER and Medicare for less invasive procedures. CONCLUSIONS: The agreement of SEER and Medicare data appears to be good for major surgical procedures and for excluding persons who did not undergo cancer-directed surgery. Both the SEER and the Medicare data captured a small number of surgeries not reported in the other file. Therefore, where possible, using both data sources will enhance identification of surgeries. Because the analysis was performed with linked data, the accuracy of surgical claims in Medicare data alone cannot be assessed.

Health Services Research↗
PubMed2002

Studying radiation therapy using SEER-Medicare-linked data.

BACKGROUND: Numerous studies have used the SEER or Medicare data to assess the use of radiation therapy. However, the completeness of these data has not been evaluated. METHODS: Using linked SEER-Medicare data, a cohort was created that included incident cases of breast, endometrial, lung, prostate, or rectal cancer from 1991 to 1996 in persons 65 years and older. For each of these cases, use of radiation therapy as an initial course of treatment reported from the SEER data was compared with use of radiation therapy in the months following diagnosis, as determined from the Medicare claims. RESULTS: Overall, there was a high agreement between SEER and Medicare sources for use of radiation therapy. Agreement was 88% for lung cancer, 93% for prostate cancer, 94% for rectal and breast cancers, and 95% for endometrial cancer. Within the Medicare files, radiation claims were found in MedPAR Physician Supplier Part B and Outpatient files. CONCLUSIONS: There is a high level of agreement between SEER and Medicare reporting of radiation treatments after a cancer diagnosis, suggesting that either source can be used to assess radiation-related treatment patterns. However, for the most complete ascertainment of radiation use, both SEER and Medicare sources should be used.

Aged↗
PubMed2002

Utility of the SEER-Medicare data to identify chemotherapy use.

BACKGROUND: Medicare claims include codes for chemotherapy administration and specific drugs given, and researchers are increasingly using these data to measure the use of chemotherapy. However, the validity and completeness of these data as a source of information has not been established. OBJECTIVES: This analysis is intended to assess the utility of the Medicare claims to capture chemotherapy use. METHODS: Persons with breast, colorectal, and ovarian cancer were identified from the linked SEER-Medicare data. Their Medicare claims were reviewed to determine if there were any bills for chemotherapy, and if so, if there were claims for specific agents. This information was compared with data on the first course of treatment obtained from hospitals and treating physicians by the SEER registries through an NCI-supported Patterns of Care Studies (POC). Agreement was measured using kappa statistics. The sensitivity of the Medicare claims to capture chemotherapy, as reported from the POC data, was also measured. An additional comparison assessed the agreement between the two data sources concerning which specific drugs had been given. RESULTS: For all of the cancers, there was a high level of agreement between the Medicare claims and the POC data regarding whether or not the patient had received chemotherapy (kappa >or=0.73). The sensitivity of the Medicare data to determine if a person had received chemotherapy was high (>or=88%). In cases where the Medicare claim included a code for a specific drug, there high agreement between Medicare and POC about the specific drug given in breast and colorectal cancers, although the agreement was lower for ovarian cancers. The sensitivity of the Medicare claims to identify specific agents varies by cancer type. CONCLUSIONS: The Medicare claims can be used to identify which persons are receiving chemotherapy. The utility of Medicare data to measure treatment with specific agents varies by cancer type and specific agent. For some cancers, it is possible to use these claims to assess use of specific drugs, while for other drugs the data are limited.

Aged↗