The impact of maternal adiposity specialization on infant birthweight: upper versus lower body fat.

BACKGROUND: The specialization of human fat deposits is an inquiry of special importance in the study of fetal growth. It has been theorized that maternal lower-body fat is designated specifically for lactation and not for the growth of the fetus. OBJECTIVE: Our goal was to compare the contributions of maternal upper-body versus lower-body adiposity to infant birth weight. We hypothesized that upper-body adiposity would be strongly associated with infant birth weight and that lower-body adiposity would be weakly or negligibly associated with infant birth weight-after adjusting for known determinants. STUDY DESIGN: In this prospective cohort study, 355 women initiated medical pre-natal care during the first trimester of pregnancy at The University of Oklahoma Health Sciences Center during 1990-1993. Maternal anthropometric measurements were assessed at the first clinic visit: (a) height; (b) weight; (c) circumferences of the upper arm, forearm, and thigh; and, (d) skin-fold measurements of the bicep, subscapular region, and thigh. RESULTS: Infant birth weight was regressed on known major determinants to create the foundational model. Maternal anthropometric variables subsequently were added one at a time into this multiple regression model. The highest contribution by a single anthropometric variable to infant birthweight was, in order: subscapular skin-fold, forearm circumference, and thigh circumference. With one upper-body (subscapular skin-fold) and one lower-body (circumference of the thigh) adiposity measure in the model, the z-score regression coefficient (s.e.) was 85.7g (30.8) [p=0.0057] for maternal subscapular skin-fold and 19.0g (31.6) [p=0.5477] for circumference of the thigh. When the second-best upper-body contributor to infant birthweight (circumference of the forearm) was entered with one lower-body measure into the model, the z-score regression coefficient (s.e.) was 77.5g (38.5) [p=0.0451] for maternal forearm circumference and 14.1g (38.5) [p=0.7146] for circumference of the thigh. When both subscapular skinfold and forearm circumference were added to the model in place of BMI, the explained variance (r2=0.5478) was similar to the model using BMI (r2=0.5487). CONCLUSION: Upper-body adiposity - whether operationalized by subscapular skin-fold or circumference of the forearm - was a markedly larger determinant of infant birth weight than lower-body adiposity.

Method of presenting oncology treatment outcomes influences patient treatment decision-making in metastatic colorectal cancer.

BACKGROUND: The methods used to communicate relevant outcomes in oncology to patients will likely influence treatment decisions. The purpose of this study was to examine the influence of three different methods of describing the efficacy of therapy on treatment decisions regarding management of metastatic colorectal cancer. METHODS: Participants reviewed a clinical scenario and randomly received one of three ways of describing efficacy of chemotherapy in metastatic colorectal cancer: (1) relative risk reduction, (2) tumor response rate, and (3) median overall survival. They received the same clinical scenario but were presented four treatment options: (1) observation and supportive care, (2) chemotherapy, (3) surgery, and (4) surgery and chemotherapy and the accompanying median overall survival estimate. RESULTS: Participants included 102 preclinical medical students. In the first scenario, 85% chose chemotherapy in the relative risk reduction group, as did 88% of the tumor response rate group, but significantly fewer participants did so in the median overall survival group (35%; P < .001). In the second scenario, there was a significant difference in treatment preferences, with 4% of participants choosing observation/supportive care. None chose chemotherapy only, 19% chose surgery only, and 77% chose surgery plus chemotherapy (P < .001). CONCLUSIONS: This study demonstrated that different methods of describing oncology treatment outcomes associated with therapy for metastatic colorectal cancer to the liver can have a dramatic effect on patient treatment decisions.

Elective cesarean section to prevent anal incontinence and brachial plexus injuries associated with macrosomia--a decision analysis.

Our aim was to determine the cost-effectiveness of a policy of elective C-section for macrosomic infants to prevent maternal anal incontinence, urinary incontinence, and newborn brachial plexus injuries. We used a decision analytic model to compare the standard of care with a policy whereby all primigravid patients in the United States would undergo an ultrasound at 39 weeks gestation, followed by an elective C-section for any fetus estimated at > or =4500 g. The following clinical consequences were considered crucial to the analysis: brachial plexus injury to the newborn; maternal anal and urinary incontinence; emergency hysterectomy; hemorrhage requiring blood transfusion; and maternal mortality. Our outcome measures included (1) number of brachial plexus injuries or cases of incontinence averted, (2) incremental monetary cost per 100,000 deliveries, (3) expected quality of life of the mother and her child, and (4) "quality-adjusted life years" (QALY) associated with the two policies. For every 100,000 deliveries, the policy of elective C-section resulted in 16.6 fewer permanent brachial plexus injuries, 185.7 fewer cases of anal incontinence, and cost savings of $3,211,000. Therefore, this policy would prevent one case of anal incontinence for every 539 elective C-sections performed. The expected quality of life associated with the elective C-section policy was also greater (quality of life score 0.923 vs 0.917 on a scale from 0.0 to 1.0 and 53.6 QALY vs 53.2). A policy whereby primigravid patients in the United States have a 39 week ultrasound-estimated fetal weight followed by C-section for any fetuses > or =4500 g appears cost effective. However, the monetary costs in our analysis were sensitive to the probability estimates of urinary incontinence following C-section and vaginal delivery and the cost estimates for urinary incontinence, vaginal delivery, and C-section.

Preferences for different methods of communicating information regarding adjuvant chemotherapy for breast cancer.

Many patients play an active role in determining their cancer treatments, and the communication of medical information influences patient decision-making. This study examined participants' preferences between various methods of communicating quantitative risks and benefits of adjuvant chemotherapy. Using clinical vignettes, participants were first asked to decide whether or not to endorse chemotherapy and were subsequently asked about their preferences for the methods used to communicate the risks and benefits. Participants preferred the absolute survival benefit method over negatively framed methods, such as relative or absolute risk reduction. We also present analysis of qualitative data which supports the conclusions drawn from quantitative analyses. In summary, the absolute survival benefit was shown to be the superior method of communicating quantitative risks and benefits of chemotherapy. Failure to use clear and concise methods of communicating quantitative risk and benefit information may compromise efforts to obtain informed consent for treatment.

Predicting the outcome of carpal tunnel release.

PURPOSE: To test the hypothesis that the result of steroid injection in the carpal tunnel provides a better predictor of the outcome of later surgery. We also explored other possible factors that might predict the outcome directly or interact with the results of steroid injection to better predict the outcome. METHOD: We performed a historical cohort study on 57 patients who had carpal tunnel release. Care was taken to avoid problems of statistical nonindependence caused by both hands being studied and confounding from previous surgeries. RESULTS: We found a large and significant difference in the success rate of surgery for patients who had obtained some relief from injection (87%) versus those who had not (54%). No other significant predictor was found. We discovered factors that may interact with the results of injection in predicting the outcome of surgery (eg, Katz and Stirrat hand diagram assessment of the probability of carpal tunnel syndrome) although not significant in our study. CONCLUSIONS: Some relief from steroid injection is the best predictor for success of surgery. Further study is warranted to identify factors that interact with this predictor.

Optimal use of sentinel lymph node biopsy versus axillary lymph node dissection in patients with breast carcinoma: a decision analysis.

BACKGROUND: There are no data available from randomized controlled trials that compare the efficacy of sentinel lymph node (SLN) biopsy with Level I/II axillary lymph node dissection (ALND) in patients with breast carcinoma. We performed a formal decision analysis to determine whether SLN biopsy is appropriate, compared with ALND, for patients with T1, T2, and T3 tumors and to quantify the relative value of these two procedures in the management of patients with breast carcinoma. METHODS: All clinically relevant outcomes were modeled for both SLN biopsy and ALND. The probabilities of complications and outcomes were derived using data from the University of Louisville Breast Cancer Sentinel Lymph Node Study and from extensive review of previous studies. Utilities were assigned by the authors, incorporating values from the literature whenever possible. RESULTS: The expected utility of SLN biopsy was higher than the expected utility for ALND for T1 and T2 tumors that were 4.0 cm or smaller. There was no clear preference for either procedure with tumors that were larger than 4.0 cm. The T1 and T2 results were robust to sensitivity analysis. CONCLUSIONS: The results of this decision analysis suggest that SLN biopsy is preferred over ALND for patients with breast tumors that are 4.0 cm or smaller. Patients should be aware of the potential for false-negative results in SLN biopsy, but this risk is outweighed by the decreased morbidity associated with the procedure itself.