Biomedical subjects

S C Morton

Publications and source records attributed to S C Morton.

45 records · Page 3Linked to original sources

PubMed1995

A meta-analysis of infant outcomes after breech delivery.

OBJECTIVE: To estimate the risks of neonatal morbidity and mortality associated with a trial of labor and with elective cesarean for the term breech infant. DATA SOURCES: Using the terms "breech," "malpresentation," and "external cephalic version," we used the MEDLINE and Health Planning and Administration data bases to search the English-language literature from January 1981 to June 1993. The search was supplemented with a review of the reference lists of key articles and text chapters. METHODS OF STUDY SELECTION: We included randomized trials or cohort studies that specified selection criteria for a vaginal delivery, provided detailed outcome data, and allowed for analysis by intended mode of delivery. DATA EXTRACTION AND SYNTHESIS: Nine studies met the inclusion criteria. We pooled the weighted results from these studies to estimate the risks of birth injuries and perinatal death, and the risk differences between trial of labor and no trial of labor groups. The pooled risk for any injury was 1.00% after a trial of labor and 0.09% after elective cesarean. For any injury or death, the risk was 1.23% after a trial of labor and 0.09% after elective cesarean. The risk differences for injury and injury or death were 0.89 and 1.10%, respectively. These are significantly different from zero, suggesting an increased risk of injury and injury or death after a trial of labor. CONCLUSION: When management decisions are made, the potential increased risk of neonatal morbidity after a trial of labor should be considered along with the increased maternal risk from cesarean delivery.

Birth Injuries↗

PubMed1995

An experimental evaluation of residential and nonresidential treatment for dually diagnosed homeless adults.

Homeless adults with both a serious mental illness and substance dependence (N = 276) were randomly assigned to: (1) a social model residential program providing integrated mental health and substance abuse treatment; (2) a community-based nonresidential program using the same social model approach; or (3) a control group receiving no intervention but free to access other community services. Interventions were designed to provide 3 months of intensive treatment, followed by 3 months of nonresidential maintenance. Subjects completed baseline interviews prior to randomization and reinterviews 3, 6, and 9 months later. Results showed that, while substance use, mental health, and housing outcomes improved from baseline, subjects assigned to treatment conditions differed little from control subjects. Examination of the relationship between length of treatment exposure and outcomes suggested that residential treatment had positive effects on outcomes at 3 months, but that these effects were eroded by 6 months.

Adult↗

PubMed1995

A survey of current problems in meta-analysis. Discussion from the Agency for Health Care Policy and Research inter-PORT Work Group on Literature Review/Meta-Analysis.

The United States Agency for Health Care Policy and Research brought together representatives from each of the Patient Outcomes Research Teams (PORTs) as the Inter-PORT Meta-Analysis Work Group. The purpose of the meeting was to discuss a wide range of problems the panel had encountered in the area of meta-analysis. Several actual problems were presented, and tentative solutions to those problems were given. The PORTs had to consider issues such as quality assessment, survival analysis, rare events, sensitivity and specificity, and random effects models. The solutions presented represent the methods used by several researchers who are active in the area of meta-analysis.

Evaluation Studies as Topic↗

PubMed1994

An examination of the Resource-Based Relative Value Scale cross-specialty linkage method.

The Resource-Based Relative Value Scale (RBRVS) was developed by surveying panels of physicians from single specialties, then merging the specialty-specific results into a common work scale. The merging process involved two steps: 1) specification of links or equivalent services across specialties: and 2) use of links to align work values from each specialty onto a common scale. This study examines the sensitivity of physician relative values of work (RVWs) to changes in both the specification of links and in the method for aligning specialties. Using the same survey data employed in developing the RBRVS, we calculated new RVWs based on an alternative specification of links and an alternative method for aligning specialties. Total RVWs declined by almost 50% for anesthesiology, and increased by more than 20% for allergists, neurologists, and thoracic surgeons. Most of this change was attributable to our specification of links. We conclude that future use of the linkage procedure employed in developing the RBRVS is not warranted without further research. Instead, efforts to update and revise work values could be based on a common scale of work developed by cross-specialty panels, thus eliminating the need for a linkage procedure.

Economics, Medical↗

PubMed1994

Panel processes for revising relative values of physician work. A pilot study.

In this study, a set of meetings was conducted to pilot a group-discussion-based method anchored by a reference set of services with agreed-on values for revising the Medicare Resource-Based Relative Value Scale (RBRVS). The authors focused on the method as it evolved over the sequence of meetings, rather than on whether the relative values of work obtained were more or less valid than relative values of work obtained elsewhere. Four pilot panels, composed of 46 physicians from different specialties (including primary care), were conducted to rate total physician work. One panel examined 80 urologic services, another panel examined 80 ophthalmologic services, and the last two panels considered the merit of appeals from five specialty and subspecialty societies to 68 and 48 services, respectively. Rather than using the method of ratio estimation relative to a standard service, panelists were asked to estimate magnitudes relative to an established multispecialty reference set of values. Prominent members of that reference set were graphically displayed to panelists on a "ruler." Measures included physicians' preliminary and final ratings and detailed notes of the group discussions conducted between the ratings. The authors found that a panel process for refining relative values of work is practical, provided that panelists are provided with a valid reference set for comparison purposes and provided that care is taken that all members feel comfortable engaging in the discussion. In Summer 1992, the Health Care Financing Association conducted a series of multispecialty panels based on the methods presented here to produce the 1993 RBRVS; in addition, the RBRVS Update Committee of the American Medical Association is employing group processes and a reference set in determining the relative work values of new Current Procedural Terminology codes.

Economics, Medical↗

PubMed1994

Effect of epidural analgesia for labor on the cesarean delivery rate.

OBJECTIVE: To use meta-analysis to evaluate the effect of epidural analgesia on the cesarean delivery rate. DATA SOURCES: The MEDLINE data base was searched for articles published in English between January 1981 and April 1992. We also interviewed experts and conducted a bibliographic follow-up and manual review of recent journals published from April to July 1992. METHODS OF STUDY SELECTION: We excluded articles with irrelevant titles, and those case studies, book chapters, or articles that did not provide primary and relevant data. Two hundred thirty articles were read, including articles that reported on women of standard obstetric risk and on cesarean delivery rates for an epidural group and for a concurrent no-epidural group. These criteria yielded six studies for a primary analysis and two others for a secondary analysis. DATA EXTRACTION AND SYNTHESIS: The sample size of the epidural and no-epidural groups and the number of cesareans within each group were extracted. Tests of homogeneity were conducted. The pooled cesarean delivery risk difference as a result of epidural analgesia was estimated. The cesarean rate for women undergoing epidural analgesia was ten percentage points greater than for no-epidural women (P < .05). More than a nine percentage point increase was shown for cesarean deliveries for dystocia (P < .05), when pooling either all studies or only randomized studies. CONCLUSIONS: The results of this meta-analysis strongly support an increase in cesarean delivery associated with epidural analgesia. Further research should evaluate the balance between analgesia associated with the use of epidurals, and postpartum morbidity and costs associated with cesarean deliveries.

Analgesia, Epidural↗

PubMed1993

Statistical quantification of 24-hour and monthly variabilities of spontaneous otoacoustic emission frequency in humans.

Previous evidence has suggested a relationship between spontaneous otoacoustic emissions (SOAEs) and established, biological cycles, although detailed statistical quantifications of the suggested relationships do not exist in the literature. In an attempt to statistically quantify the purported circadian and monthly influences on this phenomenon, two experiments were undertaken. The first experiment was conducted over eight weeks, investigating 31 SOAEs recorded from eight women and two men. Time series statistical analysis examined whether daily, weekly, and/or monthly cycles characterized SOAE frequency variability. Results yielded a significant monthly cycle for the majority of SOAEs recorded from the women but for none of the SOAEs recorded from the men. These results suggest the possibility that SOAE frequency fluctuation in women may be entrained to the monthly menstrual cycle. In the second experiment, hourly SOAE frequency stability was examined over a 24-h period to ascertain the nature of the daily frequency variation as precisely as possible. Four SOAEs from two subjects were examined, and time series analysis of these data included (1) modelling the autocorrelation structure of the measurements, (2) resolving each 24-h series of measurements into cyclical components of various periodicities, and (3) testing the statistical significance of given cycles within the spectrum of each series. Findings included a significant 24-h variability of frequency for each SOAE, suggesting the possibility of a circadian influence on frequency fluctuation. Results from the two experiments provide quantitative evidence supporting a hypothetical relationship between SOAEs and established, biological cycles.

Acoustics↗

PubMed1992

Rate-based calculation of failure to progress: a proposed quality improvement method.

The rate of "failure to progress" as the indication for primary cesarean delivery used by the Joint Commission on Accreditation of Health Care Organizations is based upon the total number of cesareans performed for this indication divided by the total number of primary cesareans. This denominator includes a large number of patients who are not at risk for the diagnosis of failure to progress, including cases of malpresentation or multiple gestation in which cesarean is performed without trial of labor. Each of these variables may vary dramatically between individual physicians and institutions. Inclusion of patients not at risk for failure to progress results in a misclassification bias, which renders this rate less meaningful for purposes of comparison and trend assessment. We describe a simple method that bases the rate of failure to progress upon the population at risk for this diagnosis; that is, the total number of vaginal deliveries plus primary cesareans for failure to progress minus vaginal births after cesarean. Such a method controls for multiple differences in local practice standards and allows more meaningful assessment of trends and intra-institutional and inter-regional comparisons.

Bias↗

PubMedDate not supplied

Variations in the care of HIV-infected adults in the United States: results from the HIV Cost and Services Utilization Study.

CONTEXT: Studies of selected populations suggest that not all persons infected with human immunodeficiency virus (HIV) receive adequate care. OBJECTIVE: To examine variations in the care received by a national sample representative of the adult US population infected with HIV. DESIGN: Cohort study that consisted of 3 interviews from January 1996 to January 1998 conducted by the HIV Cost and Services Utilization Consortium. PATIENTS AND SETTING: Multistage probability sample of 2864 respondents (68% of those targeted for sampling), who represent the 231400 persons at least 18 years old, with known HIV infection receiving medical care in the 48 contiguous United States in early 1996 in facilities other than emergency departments, the military, or prisons. The first follow-up consisted of 2466 respondents and the second had 2267 (65% of all surviving sampled subjects). MAIN OUTCOME MEASURES: Service utilization (<2 ambulatory visits, at least 1 emergency department visit that did not lead to hospitalization, at least 1 hospitalization) and medication utilization (receipt of antiretroviral therapy and prophylaxis against Pneumocystis carinii pneumonia). RESULTS: Inadequate HIV care was commonly reported at the time of interviews conducted from early 1996 to early 1997 but declined to varying degrees by late 1997. Twenty-three percent of patients initially and 15% of patients subsequently had emergency department visits that did not lead to hospitalization, 30% initially and 26% subsequently of those who had CD4 cell counts below 0.20 x 10(9)/L did not receive P carinii pneumonia prophylaxis, and 41% initially and 15% subsequently of those who had CD4 cell counts below 0.50 x 10(9)/L did not receive antiretroviral therapy (protease inhibitor or nonnucleoside reverse transcriptase inhibitor). Inferior patterns of care were seen for many of these measures in blacks and Latinos compared with whites, the uninsured and Medicaid-insured compared with the privately insured, women compared with men, and other risk and/or exposure groups compared with men who had sex with men even after CD4 cell count adjustment. With multivariate adjustment, many differences remained statistically significant. Even by early 1998, fewer blacks, women, and uninsured and Medicaid-insured persons had started taking antiretroviral medication (CD4 cell count adjusted P values <.001 to <.005). CONCLUSIONS: Access to care improved from 1996 to 1998 but remained suboptimal. Blacks, Latinos, women, the uninsured, and Medicaid-insured all had less desirable patterns of care. Strategies to ensure optimal care for patients with HIV requires identifying the causes of deficiency and addressing these important shortcomings in care.

Adult↗