Polytetramethylglykolid. I. Synthese und Eigenschaften von Polytetramethylglykolid

α-Hydroxyisobutyric acid was dimerised by azeotropic dehydration to give tetramethyl glycolide (TMG) in a yield of 70 percent. Polymerization of TMG in bulk at 120 to 140°C with lithium tert-butylate as initiator gives polytetramethyl glycolide (PTMG) of molecular weights up to 250,000 in a yield of more than 90 percent. The mechanism of polymerization is discussed. PTMG can be processed thermoplastically into a hard, brittle glass of relatively high tensile strength, flexural strength and ball indentation hardness, though of low impact strength. Solutions of the polymer can be processed to films.     

Characteristics of women refusing follow-up for tests or symptoms suggestive of breast cancer

BACKGROUND: Delay in diagnosis of breast cancer can occur at several points on the diagnostic pathway. We examined characteristics of women with breast cancer who before diagnosis actively refused recommended follow-up of tests or symptoms suggestive of breast cancer. METHODS: We identified women aged 50 years or older diagnosed with late-stage (metastatic disease or tumors > or = 3 cm at diagnosis) and a matched sample of women with early-stage (tumors < 3 cm) breast cancer from 1995 to 1999. Using medical records, we investigated clinical characteristics, use of health care, and documentation of care refusal during the 3 years before diagnosis. We used logistic regression models to compare refusers to nonrefusers. RESULTS: Of the 2694 women studied, 7.2% refused provider follow-up advice during the 3 years. These women were more likely to have late-stage breast cancer at diagnosis than were nonrefusers (odds ratio [OR] = 1.9, 95% confidence interval [CI] = 1.4 to 2.6). They were more likely to be aged 75 years or older (OR = 1.9, 95% CI = 1.4 to 2.7 compared with age 50-64) or to have six or more children (OR = 2.3, 95% CI = 1.3 to 4.2 compared to women with one to two children). Clinical factors associated with refusal included low use of mammography, high use of clinical breast exam, and missed appointments. A minority of women who refused had a reason documented in the medical record; the most frequent reasons were avoidance-denial-fatalism, fear of diagnostic tests, and fear of surgery or disfigurement. CONCLUSIONS: Our results suggest that certain demographic and clinical characteristics are associated with women's refusal of diagnostic testing for breast cancer. Further study is needed on refusers' characteristics and on how such refusals affect outcomes. Efforts aimed at identifying and counseling women with abnormal results who refuse follow-up are warranted.     

Women's decision-making roles regarding contralateral prophylactic mastectomy

BACKGROUND: Contralateral prophylactic mastectomy (CPM) is the removal of a nonaffected breast in a woman with unilateral breast cancer and is effective in reducing the risk of recurrences. Little is known about women's decision-making roles regarding CPM. METHODS: Women aged 18-80 years with CPM performed at one of six health maintenance organizations between 1979 and 1999 were surveyed. We determined women's reported decision-making roles at the time of CPM, analyzed their trends over time, and explored the association between decision-making roles and psychosocial outcomes following CPM. RESULTS: We received 562 responses (response rate = 73%); 431 completed items needed for this analysis. Most respondents were white, younger than 55 years at CPM, married, and had CPM within 10 years of completing the survey. Forty-five percent made the decision to undergo CPM alone, 37% considered their doctor's opinion, 15% shared the decision with their doctor and only 3% reported their doctor primarily made the decision. Women reporting active roles were more likely to be younger (P<.0008), college educated (P<.0001) and have CPM more recently (P = .002). Compared with those sharing the decision with their doctors, women with active roles were twice as likely to be satisfied 6 months following CPM (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.1 to 4.2) and report current concern about breast cancer (OR = 1.9, 95% CI = 1.0 to 3.4). CONCLUSIONS: Most women reported active or shared roles in decision making regarding CPM, particularly younger women, those with college education, and those with recent CPM. Women with active roles were more often satisfied in the short term but were also more likely to report current concern about breast cancer. Whether higher concern is related to insufficient input from clinicians should be explored. Prospective data are needed.     

Complications following bilateral prophylactic mastectomy

BACKGROUND: Bilateral prophylactic mastectomy significantly decreases breast cancer risk, but complications of the procedure have only been described in single-site studies. We describe the frequency and type of complications in women who underwent bilateral prophylactic mastectomy in a multisite community-based cohort. METHODS: Women aged 18-80 years undergoing bilateral prophylactic mastectomy without a personal history of breast cancer at one of six health plans were eligible. We identified women from automated data sources, then reviewed hospital data, ambulatory notes, and other chart elements to confirm eligibility and obtain all charted information about complications and surgeries performed after prophylactic mastectomy, including reconstructive procedures. Reconstructions were characterized by type (implant vs. tissue graft). Complications were noted for a 1-year period after any surgical procedure. RESULTS: We identified 269 women with prophylactic mastectomy who were followed for a mean of 7.4 years. Their mean age was 44.9 years. Nearly 80% undertook reconstruction, most with prosthetic implants. One or more complications occurred in 64%. The most common complications were pain (35% of women), infection (17%), and seroma (17%). Women with no reconstruction had fewer complications (mean of .93) than women who had implant (2.0) or tissue graft (2.4) reconstruction procedures (differences from no reconstruction: 1.07 [95% confidence interval = 0.36 to 1.77] and 1.50 [95% confidence interval = 0.44 to 2.56] respectively). Delay of reconstruction after mastectomy was associated with a borderline-significant higher risk of complications (80.6%) compared to simultaneous reconstruction (64.0%, P = .055). CONCLUSION: We found that almost two-thirds of women undergoing bilateral prophylactic mastectomy had at least one complication following surgery. Further work should be done to minimize and to understand the effect of complications of bilateral prophylactic mastectomy.     

An automated data algorithm to distinguish screening and diagnostic colorectal cancer endoscopy exams

Despite questions about accuracy, automated data are used increasingly for research and quality measurement. The goal of this study was to develop an automated data algorithm designed to distinguish screening and diagnostic endoscopy (sigmoidoscopy and colonoscopy) exams. We assessed the algorithm's ability to correctly classify the exams using paper medical records as the "gold standard." The algorithm used diagnostic codes to identify the indication of the endoscopies. The algorithm's ability to classify the indication varied by endoscopy exam. The sensitivities for identifying diagnostic sigmoidoscopy and colonoscopy were 48.1% and 23.8%, respectively. The algorithm missed most of the diagnostic endoscopies. Conversely, the sensitivities for identifying screening sigmoidoscopy and colonoscopy were high (87.9% and 84.4%, respectively) but were associated with low specificities. Our findings suggest that studies relying solely on automated data overestimate screening rates if indication is not considered. The automated algorithm presented here needs further improvements to better differentiate screening from diagnostic exams.     

The first community health centers: a model of enduring value

Community health centers in the United States, first launched as a federal initiative in 1965, were rooted in models from South Africa, the American civil rights struggle, and a national commitment to address poverty. The first 2 centers, one serving a rural population in the Mississippi Delta and another a public housing project in Boston, incorporated such core principles as provision of primary care to a defined area or population; public health interventions addressing social determinants of health; emphasis on community participation; community empowerment leading to control of the new institutions; epidemiologic methods to identify problems and guide decisions; new combinations of clinical and public health personnel; and reduction of disparities in health and healthcare of the poor and minorities. The continuing relevance of these principles in today's greatly expanded health center network is reviewed.     

The Multiple Tasks Test as a predictor of falls in older adults

PURPOSE: Falls are among the most common and serious problems facing the elderly. The Berg Balance Scale (BBS) is the gold standard in measuring falls risk. With higher functioning elders, a ceiling effect is often evidenced using the BBS. The purpose of this study was to determine if the Multiple Tasks Test (MTT) when used in high functioning community dwelling elderly correlated with the BBS. Secondly, this study assessed the unidimensionality of the MTT. If a relationship existed between the performance of multiple tasks and the potential loss of balance resulting in falls, then the MTT would be more appropriate than the BBS at predicting falls in higher functioning individuals. METHODS: Twenty-two independent community dwelling older adults were tested using both the MTT and the BBS on the same day at a senior center. DATA ANALYSIS: Correlations between the BBS and the MTT ranged between -0.765 and -0.79. The results of the Guttman's scalability analysis were a plus percentage ratio of 0.75 and an index of reproducibility of 0.93. Scales with these values are regarded as having evidence of unidimensionality. SUMMARY: All of the MTT tests correlated with the BBS. In addition, the MTT was found to be unidimensional. CONCLUSION: Although the MTT correlated with the BBS and was found to be a good cumulative measure, it would benefit from continued study to examine quantifiability, validity and reliability. With further refinement and study, the MTT may be useful at discriminating fallers from non-fallers in high functioning older adults.