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Biomedical subjects

S C Stearns

Publications and source records attributed to S C Stearns.

At least 19 recordsLinked to original sources
PubMed2004

A randomised controlled trial of a tailored multifaceted strategy to promote implementation of a clinical guideline on induced abortion care.

OBJECTIVE: To evaluate the effectiveness and efficiency of a tailored multifaceted strategy, delivered by a national clinical effectiveness programme, to implement a guideline on induced abortion. DESIGN: Cluster randomised controlled trial. SETTING AND PARTICIPANTS: All 26 hospital gynaecology units in Scotland providing induced abortion care. INTERVENTION: Following the identification of barriers to guideline implementation, intervention units received a package comprising audit and feedback, unit educational meetings, dissemination of structured case records and promotion of a patient information booklet. Control units received printed guideline summaries alone. MAIN OUTCOME MEASURES: Compliance with five key guideline recommendations (primary outcomes) and compliance with other recommendations, patient satisfaction and costs of the implementation strategy (secondary outcomes). RESULTS: No effect was observed for any key recommendation: appointment with a gynaecologist within five days of referral (odds ratio 0.89; 95% confidence interval 0.50 to 1.58); ascertainment of cervical cytology history (0.93; 0.36 to 2.40); antibiotic prophylaxis or screening for lower genital tract infection (1.70; 0.71 to 5.99); use of misoprostol as an alternative to gemeprost (1.00; 0.27 to 1.77); and offer of contraceptive supplies at discharge (1.11; 0.48 to 2.53). Median pre-intervention compliance was near optimal for antibiotic prophylaxis and misoprostol use. No intervention benefit was observed for any secondary outcome. The intervention costs an average of pound 2607 per gynaecology unit. CONCLUSIONS: The tailored multifaceted strategy was ineffective. This was possibly attributable to high pre-intervention compliance and the limited impact of the strategy on factors outside the perceived control of clinical staff.

Abortion, Induced↗
PubMed2004

Systematic review of the long-term effects and economic consequences of treatments for obesity and implications for health improvement.

OBJECTIVES: To undertake a systematic review of the long-term effects of obesity treatments on body weight, risk factors for disease, and disease. METHODS: The study encompassed three systematic reviews that examined different aspects of obesity treatments. (1) A systematic review of obesity treatments in adults where the methods of the Cochrane Collaboration were applied and randomised controlled trials (RCTs) with a follow-up of at least 1 year were evaluated. (2) A systematic epidemiological review, where studies were sought on long-term effects of weight loss on morbidity and/or mortality, and examined through epidemiological modelling. (3) A systematic economic review that sought reports with both costs and outcomes of treatment, including recent reports that assessed the cost-effectiveness of pharmaceutical and surgical interventions. A Markov model was also adopted to examine the cost-effectiveness of a low-fat diet and exercise intervention in adults with obesity and impaired glucose tolerance. RESULTS: The addition of the drugs orlistat or sibutramine was associated with weight loss and generally improved risk factors, apart from diastolic blood pressure for sibutramine. Metformin was associated with decreased mortality after 10 years in obese people with type 2 diabetes. Low-fat diets were associated with continuing weight loss for 3 years and improvements in risk factors, as well as prevention of type 2 diabetes and improved control of hypertension. Insufficient evidence was available to demonstrate the benefits of low calorie or very low calorie diets. The addition of an exercise or behaviour programme to diet was associated with improved weight loss and risk factors for at least 1 year. Studies combining low-fat diets, exercise and behaviour therapy suggested improved hypertension and cardiovascular disease. Family therapy was associated with improved weight loss for 2 years compared to individual therapy. There was insufficient evidence to conclude that individual therapy was more beneficial than group therapy. Weight lost more quickly (within 1 year), from the epidemiology review, may be more beneficial with respect to the risk of mortality. The effects of intentional weight loss need further investigation. Weight loss from surgical and non-surgical interventions for people suffering from obesity was associated with decreased risk of development of diabetes, and a reduction in low-density lipoprotein cholesterol, total cholesterol and blood pressure, in the long term. Targeting high-risk individuals with drugs or surgery was likely to result in a cost per additional life-year or quality-adjusted life-year (QALY) of no more than 13,000 British pounds. There was also suggestive evidence of cost saving from treatment of people with type 2 diabetes with metformin. Targeting surgery on people with severe obesity and impaired glucose tolerance was likely to be more cost-effective at 2329 British pounds per additional life-year. Economic modelling over 6 years for diet and exercise for people with impaired glucose tolerance was associated with a high initial cost per additional QALY, but by the sixth year the cost per QALY was 13,389 British pounds. Results did not include cost savings from diseases other than diabetes, and therefore may be conservative. CONCLUSIONS: The drugs orlistat and sibutramine appear beneficial for the treatment of adults with obesity, and metformin for obese patients with type 2 diabetes. Exercise and/or behaviour therapy appear to improve weight loss when added to diet. Low-fat diets with exercise, or with exercise and behaviour therapy are associated with the prevention of type 2 diabetes and hypertension. Long-term weight loss in epidemiological studies was associated with reduced risk of type 2 diabetes, and may be beneficial for cardiovascular disease. Low-fat diets and exercise interventions in individuals at risk of obesity-related illness are of comparable cost to drug treatments. Long-term pragmatic RCTs of obesity treatments in populations with obesity-related illness or at high risk of developing such illness are needed (to include an evaluation of risk factors, morbidity, quality of life and economic evaluations). Drug trials that include dietary advice, plus exercise and/or behaviour therapy are also needed. Research exploring effective types of exercise, diet or behaviour and also interventions to prevent obesity in adults is required.

Anti-Obesity Agents↗
PubMed2001

Evolution in health and disease: work in progress.

This article surveys progress in Darwinian medicine since 1991. Evolutionary thinking has been providing an increasing flow of fresh ideas into medical science, ideas that would not be suggested by other perspectives. Recent contributions have shed new light on the evolution of virulence, of antibiotic resistance, of oocytic atresia, of menopause, of the timing of the expression of genetic disease, of links between mate choice and disease resistance, and of genomic conflict between mother and fetus over resource provisioning. An important consequence of changes from the environment of evolutionary adaptedness concerns reproductive cancers; the incidence of reproductive cancers may be linked to changes in the frequency of menstruation in postindustrial societies. Other intriguing developments include some unanticipated and undesirable consequences of good hygiene, hope from an unexpected quarter for progress on nerve and muscle regeneration, evolutionary interpretations of mental disease, and insights from functional genomics into the nature of tradeoffs. The application of evolutionary thinking to problems in medical research and practice has thus yielded an abundant and growing harvest of insights. Some are well founded, others remain speculative. The field is moving from an initial phase dominated by speculation and hypothesis formation into a more rigorous phase of experimental testing of explicit alternatives. Currently the most promising areas, those in which experimental rigor can be applied efficiently, include experimental evolution and functional genomics. The pioneers can be proud of what they have set in motion.

Adaptation, Physiological↗
PubMed2001

Decline in offspring viability as a manifestation of aging in Drosophila melianogaster.

The evolutionary explanation of senescence proposes that selection against alleles with deleterious effects manifested only late in life is weak because most individuals die earlier for extrinsic reasons. This argument also applies to alleles whose deleterious effects are nongenetically transmitted from mother to progeny, that is, that affect the performance of progeny produced at late ages rather than of the aging individuals themselves. We studied the effect of maternal age on offspring viability (egg hatching success and larva-to-adult survival) in two sets of Drosophila melanogaster lines (HAM/LAM and YOUNG/OLD), originating from two long-term selection experiments. In each set, some lines (HAM and YOUNG, respectively) have been selected for early reproduction, whereas later reproduction was favored in their counterparts (LAM and OLD). In the HAM and LAM lines, both egg hatching success and larval viability declined with mother's age and did so with accelerating rates. The hatching success declined significantly faster with maternal age in HAM than in LAM lines, according to one of two statistical approaches used. Egg hatching success also declined with maternal age in YOUNG and OLD lines, with no difference between the selection regimes. However, the relationship between mother's age and offspring larva-to-adult viability differed significantly between these two selection regimes: a decline of larval viability with maternal age occurred in YOUNG lines but not in OLD lines. This suggests that the rate with which offspring viability declines with mother's age responded to selection for early versus late reproduction. We suggest broadening the evolutionary concept of senescence to include intrinsically caused declines in offspring quality with maternal age.

Aging↗
PubMed2001

Treatment outcomes and costs of dental sealants among children enrolled in Medicaid.

OBJECTIVES: This retrospective cohort analysis of children enrolled in the North Carolina Medicaid program compared the likelihood of restorative treatments and associated cumulative Medicaid expenditures for teeth with or without dental sealants. METHODS: We assessed the dental experience of the cohort of 15 438 children from 1985 to 1992 on the basis of enrollment and claims files. We conducted regression analyses for outcomes (caries-related services involving the occlusal surface [CRSOs] of permanent first molars) and cumulative expenditures, controlling for characteristics of the child, the treating dentist, and the child's county of residence. RESULTS: Overall, 23% of children received at least 1 sealant and 33% at least 1 CRSO. Sealants were effective in preventing CRSOs, although the degree of effectiveness was highest for children with the greater levels of CRSOs before sealant placement. Estimated cumulative Medicaid expenditures indicated expenditure savings from sealants within 2 years of application for children with 2 or more prior CRSOs. CONCLUSIONS: Sealant placement was associated with expenditure savings to Medicaid for certain high-risk children, so Medicaid and, more broadly, society will benefit by providing for sealant placement in these children.

Child↗
PubMed2000

Experimental evolution of aging, growth, and reproduction in fruitflies.

We report in this paper an evolutionary experiment on Drosophila that tested life-history theory and the evolutionary theory of aging. As theory predicts, higher extrinsic mortality rates did lead to the evolution of higher intrinsic mortality rates, to shorter lifespans, and to decreased age and size at eclosion; peak fecundity also shifted earlier in life. These results confirm the key role of extrinsic mortality rates in the evolution of growth, maturation, reproduction, and aging, and they do so with a selection regime that maintained selection on fertility throughout life while holding population densities constant.

Aging↗
PubMed2000

Life history evolution: successes, limitations, and prospects.

Life history theory tries to explain how evolution designs organisms to achieve reproductive success. The design is a solution to an ecological problem posed by the environment and subject to constraints intrinsic to the organism. Work on life histories has expanded the role of phenotypes in evolutionary theory, extending the range of predictions from genetic patterns to whole-organism traits directly connected to fitness. Among the questions answered are the following: Why are organisms small or large? Why do they mature early or late? Why do they have few or many offspring? Why do they have a short or a long life? Why must they grow old and die? The classical approach to life histories was optimization; it has had some convincing empirical success. Recently non-equilibrium approaches involving frequency-dependence, density-dependence, evolutionary game theory, adaptive dynamics, and explicit population dynamics have supplanted optimization as the preferred approach. They have not yet had as much empirical success, but there are logical reasons to prefer them, and they may soon extend the impact of life history theory into population dynamics and interspecific interactions in coevolving communities.

Aging↗
PubMed2000

Life-history correlates of evolution under high and low adult mortality.

Life-history theory predicts evolutionary changes in reproductive traits and intrinsic mortality rates in response to differences in extrinsic mortality rates. Trade-offs between life- history traits play a pivotal role in these predictions, and such trade-offs are mediated, at least in part, by physiological allocations. To gain insight into these trade-offs, we have been performing a long-term experiment in which we allow fruitflies, Drosophila melanogaster, to evolve in response to high (HAM) and low (LAM) adult mortality rates. Here we analyze the physiological correlates of the life-history trade-offs. In addition to changing development time and early fecundity in the direction predicted, high adult mortality affected three traits expressed early in life-body size, growth rate, and ovariole number-but had little or no effect on body composition (relative fat content), viability, metabolic rate, activity, starvation resistance, or desiccation resistance. Correlations among lines revealed trade-offs between early fecundity, late fecundity, and starvation resistance, which appear to be mediated by differential allocation of lipids.

Animals↗
PubMed2000

Access to care for rural Medicare beneficiaries.

This paper examines variations between urban and rural Medicare beneficiaries in three measures of access to care: self-reported access to care, satisfaction with care received and use of services. The assessment focuses on these measures and their relationship to adjacency to metropolitan areas. Comparisons are also provided for the relative effects of adjacency versus broader access barriers such as income. Data from the 1993 Medicare Current Beneficiary Survey are used. The analyses offer several new perspectives on access in rural areas. First, as perceived by respondents, rural residence does not indicate access problems; instead, Medicare beneficiaries in rural counties that are adjacent to urban areas and that have their own city of at least 10,000 people report higher levels of satisfaction and fewer self-reported access problems than do residents of urban counties. These results may stem either from differences in rural residents' expectations regarding access or willingness to accept appropriate substitutions. Preventive vaccination rates in rural areas are on par with or better than rates by beneficiaries in urban areas. The only services where utilization in rural areas was limited relative to urban areas were preventive cancer screening for women and dental care. Development of policies to address these specific service gaps may be warranted. Low income has a more pervasive and problematic relationship to self-reported access, satisfaction and utilization than does rural residence per se.

Aged↗
PubMed2000

The economic implications of self-care: the effect of lifestyle, functional adaptations, and medical self-care among a national sample of Medicare beneficiaries.

OBJECTIVES: Self-care includes actions taken by individuals to promote or ensure their health, to recover from diseases or injuries, or to manage their effects. This study measured associations between self-care practices (lifestyle practices, adaptations to functional limitations, and medical self-care) and Medicare expenditures among a national sample of adults 65 years and older. METHODS: Regression models of Medicare use and expenditures were estimated by using the National Survey of Self-Care and Aging and Medicare claims for 4 years following a baseline interview. RESULTS: Lifestyle factors (swimming and walking) and functional adaptations (general home modifications) were associated with reductions in monthly Medicare expenditures over a 12-month follow-up period. Expenditure reductions were found over the 48-month follow-up period for participation in active sports, gardening, and medical self-care. Practices associated with increases in expenditures included smoking, physical exercise (possibly of a more strenuous nature), and specific home modifications. CONCLUSIONS: Certain self-care practices appear to have significant implications for Medicare expenditures and presumptively for the health status of older adults. Such practices should be encouraged among older adults as a matter of national health policy.

Activities of Daily Living↗
PubMed2000

The effects of Medicaid expansions and reimbursement increases on dentists' participation.

North Carolina Medicaid increased nominal Medicaid reimbursement to dentists 23% from 1988 to 1991 and doubled enrollment through eligibility expansions from 1985 to 1991. Using Medicaid claims data and panel data techniques, this analysis investigates the effect of these policy changes on the probability that a dentist participated in Medicaid, and on the number of Medicaid children seen per provider per quarter. The results suggest that eligibility expansions and reimbursement rate increases were only marginally effective in increasing access to dental services for the Medicaid population.

Child↗
PubMed1999

Competitive behavior in local physician markets.

Competition often is viewed as a mechanism for controlling cost. Competition may work well in urban areas with many providers; competition may not exist in rural areas with few providers. The authors use the empirical framework developed by Bresnahan and Reiss to analyze the entry behavior of physicians into local markets to determine the level of physician supply consistent with competitive behavior. The study estimates entry patterns for total and specialty physicians located in nonmetropolitan health service areas using longitudinal data. The authors find a surprising drop in the population increments necessary for entry by the second provider, possibly due to the unattractiveness of being the solo physician in an area. Subsequent population increments stabilize at three to five physicians. Since more than 93 percent of the U.S. population lives in areas that can support three to five physicians, competition between physicians through mechanisms such as managed care may be feasible.

Catchment Area, Health↗
PubMed1999

A tale of two bounties: the impact of competing fees on physician behavior.

This study examines how the volume of privately insured services provided in hospital inpatient and outpatient departments changes in response to reductions in Medicare physician payments. We hypothesize that physicians consider relative payment rates when choosing which patients to treat in their practices. When Medicare reduces its payments for surgical procedures, as it did in the late 1980s, physicians are predicted to treat more privately insured patients because they become more lucrative. We use data from 182 hospitals for seventeen major procedures groups, covering a forty-five-month period between 1988 and 1991 that encom passes a twenty-four-month period before the reduction in Medicare fees and twenty-one months after the reduction. Our findings are consistent with the predictions for a number of procedure groups, but not for all of them. One implication of the findings is that societal savings from Medicare fee reductions are overstated if one does not also consider spillover effects in the private insurance market.

Aged↗