Effects of physician supply on early detection of breast cancer

BACKGROUND: There are few studies examining the effects of physician supply on health-related outcomes. We hypothesized that increasing physician supply and, in particular, increasing primary care supply would be related to earlier detection of breast cancer. METHODS: Information on incident cases of breast cancer occurring in Florida in 1994 (n = 11,740) was collected from the state cancer registry. Measures of physician supply were obtained from the 1994 AMA Physician Masterfile. The effects of physician supply on the odds of late-stage diagnosis were examined using multiple logistic regression. RESULTS: There was no relation between overall physician supply and stage of breast cancer of diagnosis. Each 10th percentile increase in primary care physician supply, however, resulted in a 4% increase in the odds of early-stage diagnosis (adjusted odds ratio = 1.04, 95% confidence interval = 1.01-1.06). CONCLUSIONS: The supply of primary care physicians was significantly associated with earlier stage of breast cancer at diagnosis. This study suggests that an appropriate balance of primary care and specialty physician supply might be an important predictor of health outcomes.     

Primary care physician supply and colorectal cancer.

OBJECTIVES: Our goal was to determine if increasing primary care physician supply was associated with lower incidence and mortality rates for colorectal cancer. STUDY DESIGN: We performed an ecologic study of Florida's 67 counties, using data from the state tumor registry and the American Medical Association physician masterfile. POPULATION: Florida residents were included. OUTCOMES MEASURED: We measured age-adjusted colorectal cancer incidence and mortality rates for Florida's 67 counties during the period 1993 to 1995. RESULTS: Increasing primary care physician supply was negatively correlated with both colorectal cancer (CC) incidence (CC = -0.46; P < .0001) and mortality rates (CC = -0.29; P =.02). In linear regression that controlled for other county characteristics, each 1% increase in the proportion of county physicians who were in primary care specialties was associated with a corresponding reduction in colorectal cancer incidence of 0.25 cases per 100,000 (P < .0001) and a reduction in colorectal cancer mortality of 0.08 cases per 100,000 (P =.0008). CONCLUSIONS: Incidence and mortality of colorectal cancer decreased in Florida counties that had an increased supply of primary care physicians. This suggests that a balanced work force may achieve better health outcomes.     

The value of reasons for encounter in early detection of colorectal cancer

Background: Symptoms with a high predictive power for colorectal cancer (CRC) do not exist.

Objective: To explore the predictive value of patients’ reason for encounter (RFE) in the two years prior to the diagnosis of CRC.

Methods: A retrospective nested case-control study using prospectively collected data from electronic records in general practice over 20 years. Matching was done based on age (within two years), gender and practice. The positive likelihood ratios (LR+) and odds ratios (OR) were calculated for RFE between cases and controls in the two years before the index date.

Results: We identified 184 CRC cases and matched 366 controls. Six RFEs had significant LR?+?and ORs for CRC, which may have high predictive power. These RFEs are part of four chapters in the International Classification of Primary Care (ICPC) that include tiredness (significant at 3–6 months prior to the diagnosis; LR+ 2.6 and OR 3.07; and from 0 to 3 months prior to the diagnosis; LR+ 2.0 and OR 2.36), anaemia (significant at three months before diagnosis; LR+ 9.8 and OR 16.54), abdominal pain, rectal bleeding and constipation (significant at 3–6 months before diagnosis; LR+ 3.0 and OR 3.33; 3 months prior to the diagnosis LR+ 8.0 and OR 18.10) and weight loss (significant at three months before diagnosis; LR+ 14.9 and OR 14.53).

Conclusion: Data capture and organization in ICPC permits study of the predictive value of RFE for CRC in primary care.     

Calcium intake and colorectal adenoma in a US colorectal cancer early detection program

BACKGROUND: Calcium can reduce the risk of colorectal tumors by binding secondary bile and fatty acids, which leads to antiproliferative effects in the bowel, or by acting directly on the colonic epithelium, which affects differentiation and apoptosis. OBJECTIVE: We investigated calcium intake and risk of colon adenoma to evaluate the association of calcium intake with early stages of colorectal tumor development. DESIGN: We compared the supplemental and dietary calcium intakes of 3696 participants with histologically verified adenoma of the distal colon (ie, descending colon, sigmoid colon, or rectum) with the calcium intakes of 34 817 sigmoidoscopy-negative control participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Calcium intake was assessed at study entry with a 137-item food-frequency questionnaire and additional questions on the amount and duration of calcium supplement use. RESULTS: After adjustment for known risk factors, adenoma risk was lower by 12% for participants in the highest quintile of total calcium intake (>1767 mg/d) than for participants in the lowest quintile (<731 mg/d) (odds ratio: 0.88; 95% CI: 0.76, 1.02; P for trend = 0.04). The protective association between total calcium and colorectal adenoma was largely due to calcium supplement use, with a 27% decrease in adenoma risk for participants taking >1200 mg/d than for nonusers of supplements (odds ratio: 0.73; 95% CI: 0.56, 0.91; P for trend = 0.005). The protective associations of total and supplemental calcium were strongest for colon adenoma (descending and sigmoid colon). CONCLUSION: High calcium intake, particularly from supplements, is associated with a reduced risk of distal colorectal adenoma.     

结直肠癌筛查和早期诊断生物标志物研究进展

结直肠癌疾病负担沉重,严重威胁人类健康,人群中开展筛查可有效降低结直肠癌发病率和死亡率。近年来,结直肠癌相关的遗传学、表观遗传学和微生物组学研究成果层出不穷,随着基因测序和分子检测技术的发展,探索与癌症发生发展相关的生物标志物以应用于结直肠癌筛查和早期诊断已成为目前的研究热点。本文对现有结直肠癌筛查和早期诊断生物标志物...     

The impact of physician supply on avoidable cancer deaths in Germany. A spatial analysis

Background

Measures of avoidable deaths incorporate the notion that deaths from certain causes should not occur within specified age groups given effective prevention or timely and appropriate access to health care. The present study investigated the impact on specific types of avoidable cancer deaths (ACD) of regional variations in the supply of health services over five years using German districts (Kreise und kreisfreie Städte) as units of analysis.

Methods

Age-standardized, average ACD rates were calculated for 2000-2004 for each of the 439 districts in Germany using unit-record mortality data. The distribution of ACD was subsequently analyzed using country maps and negative binomial regression with random intercepts. Potential endogeneity of physician supply to ACD was controlled for using an instrumental variable approach.The panel data for the years 2000-2004 were merged from a range of official statistics including mortality and hospital records (DESTATIS) and statistics provided by the Federal Office for Building and Regional Planning (INKAR).

Results

In women, 27.81 per 100,000 died from preventable or treatable cancer types in an average year between 2000 and 2004. The rates for men were generally higher, with 40.07 standardized ACD per 100,000.The regression results showed that an increase in physician supply per 100,000 was significantly associated with lower ACD rates in cancer of the female breast, and cancer of the colon, rectosigmoid junction, rectum and anus in both sexes. The contribution ranged from a decrease by a factor of 0.9994 (female breast cancer) to a factor of 0.9986 (cancer of the colon, rectosigmoid junction, rectum and anus in men) in ACD rate as the physician-population ratio increased by one unit.

Conclusion

An increase in physician density tended to be associated with a small reduction in some ACD rates. We suggest that better accessibility or quality of care might have linked increased physician density with improved health outcomes.     

The impact of Medicare on early cancer detection in the elderly.

In an analysis of 23 sex-specific tumors in the Connecticut Tumor Registry, only seven tumors showed more than a 20 per cent increase in the ratio of localized tumors detected post-Medicare (1967-75) versus ante-Medicare (1960-65) in the 65-75 year age group compared to the 60-64 year age group. Of these seven, the information was more convincing for lung cancer in males. Overall, however, Medicare had little if any impact on early tumor diagnosis in the elderly.     

The role of physician reminders in faecal occult blood testing for colorectal cancer screening

Objective: To evaluate the ability of elbow extension, with the patient in a supine position, as a diagnostic test of an insignificant injury, with the purpose of avoiding unnecessary radiographs. Methods: Seventy patients suffering from an acute elbow injury were examined at the accident and emergency department. Inability to fully actively extend the elbow in a supine position was defined as a positive diagnostic test. Radiographs were interpreted by a consultant radiologist, blinded to all clinical examination results. Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios along with their 95% confidence intervals were calculated for the elbow-extension test. Results: Forty out of 70 patients had a positive test. Elbow fracture or dislocation was identified radiographically in 22 patients with positive test (sensitivity 92%). Two out of 30 (with negative test) had a hairline radial head fracture, which was found on radiographs (specificity 61%). Conclusion: Elbow extension as a diagnostic test in a primary care setting can predict severe elbow injuries and can be safely used in practices with no radiology facilities.     

蒿甲醚对人结直肠癌细胞的毒性和放疗增敏作用的 研究

摘要:目的　探讨蒿甲醚对人结直肠癌细胞株HCT116及HT29的细胞毒性和放射增敏作用。方法　采用MTT法检测蒿甲醚对人结直肠癌细胞株HCT116及HT29的细胞毒性。克隆形成实验检测蒿甲醚对人结直肠癌细胞株HCT116及HT29的放射增敏作用,多靶单击模型拟合HCT116及HT29细胞的剂量存活曲线,计算蒿甲醚对HCT116及HT29细胞的放射增敏比,评价其放射增敏效果。结果　蒿甲醚对HCT116及HT29细胞作用24 h、48 h、72 h的IC50分别为:HCT116:300 μg/ml、270 μg/ml、170 μg/ml;HT29:280 μg/ml、250 μg/ml、200 μg/ml。蒿甲醚对HCT116及HT29细胞在平均致死剂量的放射增敏比（SERD0）分别为1.31和1.25。结论　蒿甲醚对人结直肠癌细胞株HCT116及HT29的细胞毒性作用呈剂量和时间依赖性,并可对人结直肠癌细胞系HCT116及HT29有放射增敏作用。     

外源性脂肪酸对结肠癌细胞生长的影响及其可能机制

目的：探讨八种外源性脂肪酸对人结肠癌细胞生长的影响及其作用机制。方法：体外实验中应用MTT法观察外源性脂肪酸对细胞生长的影响，并对细胞脂质过氧化反应产物丙二醛含量进行了测定。结果：多不饱和脂肪酸可抑制结肠癌细胞生长，饱和及单不饱和脂肪酸作用不明显，八种脂肪酸对正常成纤维细胞没有明显抑制作用。多不饱和脂肪酸可引起细胞内丙二醛含量升高。结论：多不饱和脂肪酸可选择性抑制肿瘤细胞生长，脂质过氧化反应增强，可能是其主要作用机制。     

Increasing colorectal cancer testing: translating physician interventions into population-based practice

Colorectal cancer (CRC) screening in the Medicare population remains low despite Medicare coverage. We describe a population-based effort to increase CRC testing of Medicare enrollees in two States through promotion and distribution of office-based tools to primary care physicians and gastroenterologists. Small increases in colonoscopy test use by primary care physicians were observed, but the differences were not statistically significant. Results in one State were stronger than the other, and two components of the intervention appeared more promising than others. Use of CRC tests can be increased, but additional approaches are needed.     

Healing the poor: The influence of patient socioeconomic status on physician supply responses

A longstanding literature explores how altruism affects the way physicians respond to incentives and provide care. We analyze how patient socioeconomic status mediates these responses. We show theoretically that patient socioeconomic status systematically influences the way physicians respond to reimbursement changes, and we identify the channels through which these effects operate. We use two Medicare reimbursement changes to investigate these insights empirically. We confirm that a given physician facing an increase in reimbursement boosts utilization by more when treating richer patients. We show that average supply price elasticities vary from 0.02 to 0.18 for a given physician, depending on the patient’s socioeconomic status. Finally, we show that the Medicare reforms we study led to overall reimbursement increases that raised healthcare utilization by 10% more for high-income patients compared to their low-income peers.     

An assessment of the perceived barriers and strategies to promoting early detection of colorectal cancer: a practitioners' perspective

Colorectal cancer (CRC) is the third most common type of cancer in the United States. Of the kinds of cancers that can be detected early, it is the only type of cancer that has not shown a decrease in mortality rates. The purpose of this study was to gather information on the perceived barriers to screening for CRC from a primary health care professionals' perspective and to compile a list of suggested strategies to reduce these barriers in Tompkins County, New York. A series of structured group meetings was conducted using a Nominal Group Process (NGP) method for data collection. The most common perceived barriers were (in descending order of importance) reluctance because of fear and/or embarrassment, cost, lack of knowledge, denial, lack of providers' support, and insufficient time. The important suggested strategies to promote screening were community education, health practitioners' support, reduction of cost, better screening, providing time, and social support.     

结直肠组织肿瘤标志物检测在结直肠癌早期诊断中的应用

目的 探讨结直肠癌组织提取液肿瘤标志物浓度与血清肿瘤标志物浓度的差异及与结直肠癌早期诊疗的关系。方法 选取长沙市第一医院收治的结直肠癌患者40例,取该患者肿瘤病变部位组织和癌旁组织,分别作为癌组织组和癌旁组织组,同时选取非结直肠癌患者良性结直肠组织50例作为对照组,采用细胞破碎法提取组织细胞上清液,罗氏电化学发光法测定上清液中肿瘤标志物癌胚抗原(carcinoembryonic antigen, CEA)、糖类抗原125(carbohydrate antigen 125,CA125)和糖类抗原199(carbohydrate antigen 199,CA199)的含量,并比较其与血清CEA、CA199、CA125浓度差异,以及分析结直肠癌组织上述肿瘤标志物与临床病理特征的关系。结果 CEA、CA199、CA125浓度在癌组织组中显著高于癌旁组和对照组,癌组织组中CEA、CA199和CA125浓度均要高于血清,差异均有统计学意义(P<0.05)。CEA和CA199在癌组织组中ROC曲线面积分别为0.928和0.863,明显大于在血清中ROC曲线面积。癌组织组CEA、CA199含量与结直肠癌浸润深度和淋巴结转移成正相关,癌组织组中CEA、CA199、CA125含量均与结直肠癌TNM分期呈正相关,差异均有统计学意义(P<0.05),其中以CEA相关强度最好。结论 结直肠癌组织提取液肿瘤标志物CEA、CA199、CA125检测可用于早期辅助诊断结直肠癌,具有一定的应用价值。     

Cost savings in mass population screening for colorectal cancer resulting from the early detection and excision of adenomas.

The widely-accepted hypothesis of a development sequence from colorectal adenoma to carcinoma is felt by clinicians to legitimate adenoma excision during routine colonoscopic investigation. Using published data on adenoma development, and adenoma prevalence data derived from the Nottingham colorectal cancer screening trial, the number of carcinomas prevented by early excision as a result of screening is predicted. The cost-effectiveness of early excision is then evaluated with reference to the expected treatment costs saved. These cost savings are found to represent a discount on the overall costs of mass population screening for colorectal cancer.