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Biomedical subjects

W C Miller

Publications and source records attributed to W C Miller.

At least 37 records · Page 2Linked to original sources
PubMed2001

Rational testing of the HIV-exposed infant.

OBJECTIVES: The objectives of this study were 1) to evaluate testing regimens of human immunodeficiency virus (HIV)-exposed infants and 2) to determine optimal methods of follow-up by enzyme-linked immunosorbent assay (ELISA) testing. METHODS: We reviewed the results from 742 HIV-exposed infants in the state of North Carolina; 2474 samples were tested for HIV by DNA polymerase chain reaction (PCR) at the University of North Carolina Retrovirology Core Laboratory. We then reviewed the utility and costs of ELISA testing of all HIV-exposed infants who were seen at the Duke University Pediatric Infectious Disease Clinic between January 1, 1993, and May 5, 1998. We used likelihood ratios to model probability of HIV infection given 3 negative DNA (PCR) tests and to provide recommendations on the use of ELISA follow-up. RESULTS: The overall sensitivity of the DNA PCR was 87.1%, and its specificity was 99.9%. We evaluated 224 HIV-exposed infants who were seen at Duke University and who had at least 3 negative diagnostic tests using either DNA PCR tests or HIV blood cultures. All 178 infants who subsequently underwent ELISA testing ultimately demonstrated seroreversion. The Duke University Pediatric Infectious Disease Clinic transferred the care of 65 patients to primary care physicians before ELISA testing and retained the care of the remaining 159 patients. Children who remained in Duke's care were more likely to have documentation of seroreversion (158 of 159 vs 20 of 65). We reviewed costs of travel, physician appointment, and HIV antibody testing in a tertiary care setting. Given 3 negative PCR tests, the expected cost per case of HIV detected by a positive ELISA assay is $23.8 million. CONCLUSIONS: Documentation of seroreversion in this cohort was nearly complete in the multidisciplinary subspecialty clinic but not when such responsibility was left to the primary care physician. Given the low probability of disease in patients who have had 3 negative PCR tests, documentation of a negative ELISA may not be an appropriate use of medical resources.

Algorithms↗
PubMed2001

Prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection in pediatric private practice.

BACKGROUND: Universal screening of sexually active adolescents for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) has been recommended in settings in which prevalence is 2% or greater. Although believed to be above 2%, the prevalence of CT and GC infection in private practice settings has not been clearly established and may affect screening practices. OBJECTIVES: To determine CT and GC infection prevalence in 2 pediatric private practices. DESIGN: Cross-sectional study. SETTING: Two pediatric private practices in suburban North Carolina. PATIENTS: Convenience sample of patients aged 15 to 24 years who were seen from August 1998 through June 1999. MAIN OUTCOME MEASURES: Prevalence of CT and GC infection. RESULTS: Of 1114 eligible patients, 803 (72%) completed questionnaires and provided urine specimens tested for CT and GC infection using ligase chain reaction assays. Mean age was 17.1 years (standard deviation: 1.8). Most participants were female (63%), white (87%), and from highly educated families (64% of their mothers graduated from college). Sexual activity was reported by 41%. Prevalence of CT infection in all participants was 0.9% (confidence interval [CI]: 0.4%-1.8%); in sexually active participants, 2.1% (CI: 0.9%-4.3%); in sexually active females, 2.7% (CI: 1.0%-5.7%); and in sexually active males, 0.9% (CI: 0.0%-5.1%). One case of GC infection was found. CONCLUSIONS: The prevalence of CT and GC infection in this private practice population was much lower than reported in other settings. Screening recommendations may need to be reassessed if other low prevalence populations are found.

Adolescent↗
PubMed2001

Effective diet and exercise treatments for overweight and recommendations for intervention.

Traditional diet and exercise treatments for obesity have been ineffective in reducing the prevalence of overweight in the population. Treatment outcomes for overweight can be measured in terms of physical parameters (e.g. bodyweight, percentage body fat, body mass index), medical terms (e.g. blood pressure, blood glucose control, blood lipid levels), psychological terms (e.g. eating pathology, self-esteem, mood state) and behavioural terms (e.g. frequency of exercise, eating patterns, self healthcare). Regardless of the specific outcome measures used to define successful treatment, the desired outcome must be maintained for several years to be considered effective. Energy restrictive diets cause significant initial bodyweight loss, but are plagued with high dropout- and relapse-rate. Low-fat diets have met with minimal success for bodyweight control, but nonetheless can significantly lower blood lipid levels. High-protein/low-carbohydrate diets are claimed to be the most effective in reducing bodyweight, but there are no scientific data to support these claims. Persons on these types of diets are also at the greatest risk for metabolic adverse effects. Nondieting approaches and programmes that stress 'health at any size' have not been researched rigorously, but preliminary data show minimal bodyweight loss with significant improvements in psychological state, eating pathology and well-being. Exercise is the only variable that consistently shows effectiveness in physiological, medical, psychological and behavioural outcomes. A treatment programme that has the greatest potential for success, regardless of outcome measure, is a programme that consists of 4 key components. These components are: (i) pre-evaluation, where historical information is gathered and used to set programme goals, objectives and outcome measures; (ii) exercise, wherein enjoyable exercise is encouraged for health, bodyweight control and well being; (iii) a behavioural plan, which is based on patterns of eating and activity that will lead to the desired outcome measures; and (iv) a maintenance plan, that helps the individual develop skills for maintaining newly developed behaviours.

Behavior Therapy↗
PubMed2001

Risk assessment for gonococcal and chlamydial infections in young children undergoing evaluation for sexual abuse.

OBJECTIVE: Testing for gonorrhea (GC) and chlamydial (Ct) infection in children who are being evaluated for sexual abuse is invasive and costly. We developed selective criteria to limit unnecessary testing for these infections. METHODS: Over a 10-year period (May 1988 to May 1998), clinical information was collected in a prospectively designed database for all children ages 0 to 12 years by the WakeMed Child Sexual Abuse Team in Raleigh, North Carolina. The study population comprised 3040 (2414 girls and 626 boys) of the 3064 children evaluated for sexual abuse. Children were interviewed, examined, and tested by culture for GC and Ct orally, rectally, and genitally. Information from referral sources, accompanying guardians, and previous recent physical examinations was recorded. Bivariate analyses and logistic regression were used to develop 2 sets of screening criteria to predict children at greatest risk of infection with: 1) GC and/or Ct (GC/Ct) and 2) GC alone. RESULTS: Fifty-eight children were identified with GC/Ct infections (37 with GC, 25 with Ct; 4 children were coinfected). The proposed algorithm for GC/Ct infections would have identified all children with these infections, while avoiding testing 56% of children without infection. Using genital cultures only, the proposed risk score for GC/Ct infections would have identified 100% of GC/Ct cases with 85% fewer cultures compared with testing all children with oral, rectal, and genital cultures. CONCLUSION: The use of a risk assessment algorithm for GC and Ct infections may reduce the cost and trauma of testing young children who are being evaluated for sexual abuse. sexual abuse, gonorrhea, Neisseria gonorrhoeae, chlamydia, Chlamydia trachomatis, sexually transmitted diseases, children.

Algorithms↗
PubMed2001

Syndromic treatment of gonococcal and chlamydial infections in women seeking primary care for the genital discharge syndrome: decision-making.

The syndromic treatment of gonococcal and chlamydial infections in women seeking primary care in clinics where resources are scarce, as recommended by WHO and implemented in many developing countries, necessitates a balance to be struck between overtreatment and undertreatment. The present paper identifies factors that are relevant to the selection of specific strategies for syndromic treatment in the above circumstances. Among them are the general aspects of decision-making and caveats concerning the rational decision-making approach. The positive and negative implications are outlined of providing or withholding treatment following a specific algorithm with a given accuracy to detect infection, i.e. sensitivity, specificity and predictive values. Other decision-making considerations that are identified are related to implementation and include the stability of risk factors with regard to time, space and the implementer, acceptability by stakeholders, and environmental constraints. There is a need to consider empirically developed treatment algorithms as a basis for policy discourse, to be evaluated together with the evidence, alternatives and arguments by the stakeholders.

Algorithms↗
PubMed2000

Sex differences in nevirapine rash.

Nevirapine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) that has the most common treatment limiting side effect of rash. Severe rash has been observed in 3% of patients taking nevirapine in clinical trials, 85% of whom were men. In a multicenter, retrospective cohort study of all patients who received nevirapine over a 5-year period, severe rash was noted in 9 of 95 women and 3 of 263 men (risk ratio [RR], 8.31; 95% confidence interval [CI], 2.3-30.0; P=.005). Women were more likely to discontinue nevirapine therapy because of rash (RR, 4.5; 95% CI, 1. 9-10.5; P=.0005). After adjusting for age and baseline CD4 cell count in multivariate analysis, women had a 7-fold increase in risk for severe rash and were 3.5 times more likely to discontinue nevirapine therapy. In women of reproductive age for whom contraception may occur, nevirapine remains the NNRTI of choice. Recognition of sex differences in this severe adverse event will be important in prescribing nevirapine.

Adult↗
PubMed2000

Trends of gonorrhea and chlamydial infection during 1985-1996 among active-duty soldiers at a United States Army installation.

High rates of sexually transmitted diseases (STDs) have been reported in military populations. However, it remains uncertain whether the incidence of STDs is higher among military personnel than in the civilian population. The annual incidence of gonorrhea and chlamydia from 1985 through 1996 at Fort Bragg, North Carolina, was determined by use of a clinic database and demographic information for the entire installation. A direct standardization for age, sex, and race/ethnicity was performed, and the adjusted annual rates among active duty soldiers were compared with rates among men and women in North Carolina and the United States. Results showed that the adjusted incidence of gonorrhea and chlamydia among Fort Bragg soldiers remained higher overall than comparable state and national rates during the period of analyses. The 1996 adjusted chlamydia rates for male and female active duty soldiers were 3-fold to 6-fold higher than rates for males and females in North Carolina and in the United States as a whole. STDs continue to lead to significant morbidity in this representative military population.

Adolescent↗
PubMed2000

Clinical usefulness of white blood cell count after cesarean delivery.

OBJECTIVE: To examine changes in white blood cell (WBC) count after cesarean and estimate risk of postoperative infection. METHODS: We measured complete blood cell counts at admission and on postoperative day 1 for 458 women who had cesareans. Information from charts was abstracted, and definitions of infectious outcomes and fever were applied by three physicians masked to laboratory results. We examined changes in absolute and relative WBC counts by labor status. Likelihood ratios for postoperative infection were calculated for statistically distinct categories of percentage changes. RESULTS: We excluded 60 women with chorioamnionitis. Of the remainder, 34 (8.5%) developed endometritis and three (0.8%) pneumonia. Women who labored before cesarean (n = 198) had higher antepartum (P <.001) and postoperative day 1 (P <.001) WBC counts than those who did not (n = 200). However, change in WBC count after cesarean relative to antepartum was similar for both groups (P =.41), averaging a 22% increase. We grouped percentage changes into the following three levels: up to 24%, 25-99%, and at least 100%. The lowest level (n = 246) corresponded to a category-specific likelihood ratio for diagnosis of serious postpartum infection of 0. 5 (95% confidence interval [CI] 0.3, 0.8), the midlevel (n = 141) to a category-specific likelihood ratio of 1.7 (95% CI 1.2, 2.3), and the highest level (n = 11) to a category-specific likelihood ratio of 5.8 (95% CI 1.8, 18.7). CONCLUSION: Labor influenced postcesarean WBC counts but did not obscure changes associated with infection. Information gained from changes in WBC counts can be used to assess risk of infection.

Adult↗
PubMed2000

Selective screening for chlamydial infection: which criteria to use?

BACKGROUND: Screening sexually active women for Chlamydia trachomatis is necessary to detect asymptomatic infections. Selective screening is a common strategy because universal screening is too costly in many settings. In order to guide local programs in the choice of selective screening criteria, we examined the performance of previously proposed screening criteria for C. trachomatis. METHODS: A clinic-based, cross-sectional study was conducted in public family planning and sexually transmitted disease (STD) clinics in ten counties in North Carolina. Women (n = 4471 in family planning and n = 2201 in STD clinics) undergoing pelvic examination were enrolled consecutively. Nine sets of screening criteria, including age alone, were compared using sensitivity, specificity, number of tests required and receiver-operator characteristic (ROC) analysis. All women underwent testing with ligase chain reaction assay of cervical specimens to identify C trachomatis infection. RESULTS: The prevalence of C. trachomatis was 7.8% and 11.0% in family planning and STD clinics, respectively. The sensitivities of published criteria ranged from 0.50 to 0.97. Specificities ranged from 0.05 to 0.66. In family planning clinics, the best performing criteria would detect 84% of infections while screening 51% of women. In STD clinics, the same criteria would detect 83% of infections but require testing 67% of women. Testing women aged < or =22 would detect 77% of infections in family planning and 74% of infections in STD clinics, while testing 51% and 48% of the women, respectively. CONCLUSIONS: When site-specific criteria cannot be developed, age alone is an acceptable strategy for selective screening for chlamydial infection.

Adult↗
PubMed2000

Selective screening for cervical neoplasia: an approach for resource-poor settings.

BACKGROUND: Cervical malignancies are the leading cause of cancer-related morbidity and mortality among women in developing countries. Although early detection programmes using cytological methods, followed by aggressive treatment of precursor lesions are accepted as the main disease control strategy, fiscal limitations make this strategy unfeasible in many countries. METHODS: To screen selectively, we developed two risk scores using data from a population-based case-control study in Jamaica with 202 cases and 363 controls. Independent risk factors for cervical neoplasia were determined using logistic regression. An unweighted risk score for each subject was developed by a simple count of risk factors present and a weighted risk score was calculated by summing regression coefficients for each risk factor. RESULTS: Four patient characteristics were independently predictive of cervical neoplasia, older age (OR = 3.4, 95% CI : 1.8-6.7), > or = 4 pregnancies (OR = 5.6, 95% CI : 1.2-18.7), poverty (OR = 2.1, 95% CI : 1.3-3.3) and cigarette smoking (OR = 1.9, 95% CI : 1.2-3.2). Using cut-off points of > or = 20 for the weighted scores and > 3 for unweighted scores, the sensitivity and specificity were 65% and 69% for the unweighted score and 75% and 61%, respectively, for the weighted score. Areas under the receiver operating characteristic (ROC) curves for the weighted versus the unweighted scores were similar, suggesting similar overall accuracy. CONCLUSION: Selective screening using risk assessment strategies is potentially useful, particularly in resource-poor settings. However, whether weighting factors is essential is dependent on prevalence of factors in a given setting. Although this approach needs validation in other populations, women at highest risk for cervical neoplasia can be identified using demographic factors available during a regular clinic visit.

Adult↗
PubMed2000

Clinical utility of measuring white blood cells on vaginal wet mount and endocervical gram stain for the prediction of chlamydial and gonococcal infections.

BACKGROUND: White blood cells on endocervical Gram stain and vaginal wet mount are frequently used to predict chlamydial and gonococcal infections. Previous studies provide conflicting evidence for the clinical utility of these tests. GOAL: To evaluate the clinical utility of measuring white blood cells on vaginal wet mount and endocervical Gram stain for the prediction of chlamydial infection and gonorrhea. STUDY DESIGN: Women undergoing pelvic examinations at 10 county health department family planning and sexually transmitted disease clinics were tested for chlamydial infection by ligase chain reaction assay (n = 4550) and for gonorrhea by culture (n = 4402). Vaginal wet mount and endocervical Gram stains were performed in county laboratories at the time of examination. RESULTS: The prevalences of chlamydial infection and gonorrhea were 8.8% and 3.2%, respectively. For detection of chlamydial or gonococcal infection, the likelihood ratio was 2.85 (95% CI, 2.10-3.87) for > 30 white blood cells on vaginal wet mount and 2.91 (95% CI, 2.07-4.09) for > 30 white blood cells on endocervical Gram stain. Similar results were seen for individual diagnoses either of chlamydial infection or of gonorrhea. CONCLUSION: Vaginal wet mount and endocervical Gram stain white blood cells are useful for the presumptive diagnosis of chlamydial infection or gonorrhea only in settings with a relatively high prevalence of infection or when other predictors can increase the likelihood of infection.

Adult↗
PubMed2000

Adiposity does not hinder the fitness response to exercise training in obese women.

BACKGROUND: This study examined how sedentary obese (OB) and normal weight (NW) women respond to exercise training; and if fitness levels of the OB and NW are comparable, in spite of differences in adiposity. METHODS: Sedentary OB (n=46, 48.5+/-1.5 yrs, BMI=35.9+/-0.8; mean+/-SEM) and NW (n=43, 48.3+/-1.7 yrs, BMI=21.7+/-0.2) women participated in a 14-week fitness program. RESULTS: There were no group differences in exercise adherence. No changes for either group were found for body weight or composition. Both groups improved similarly in aerobic fitness (VO2max), muscular strength (grip strength), muscular endurance (modified push-up), and flexibility (sit and reach). However, since norms for fitness are generally expressed relative to body weight (e.g. VO2max, ml x kg(-1) x min(-1); grip strength ratios), the OB women continued to be classified as unfit after exercise training, and categorized below the NW women in spite of having absolute scores for VO2max (OB=2.1+/-0.1, NW=1.8+/-0.1 l x min(-1)) and grip strength (OB=65.1+/-1.5, NW= 58.6+/-1.5 kg) that were higher than the NW women. CONCLUSIONS: The data suggest that OB women respond in a similar manner as NW women to exercise; that weight loss is not necessary for improved fitness; and that the OB are not less fit than the NW, but that low fitness scores for the OB are simply a reflection of the absolute scores being deflated because they are proportioned to body weight.

Exercise↗
PubMed1999

Detectable HIV-1 RNA at levels below quantifiable limits by amplicor HIV-1 monitor is associated with virologic relapse on antiretroviral therapy.

OBJECTIVE: To assess the clinical significance of HIV-1 RNA levels detectable using the Amplicor HIV-1 Monitor method but < 400 copies/ml versus levels undetectable by this method. DESIGN: Retrospective cohort study. METHODS: All plasma HIV-1 RNA results over 13 months in our institution were reviewed. The study population comprised all individuals that achieved an HIV-1 RNA level < 400 copies/ml and remained on stable antiretroviral therapy. Results of < 400 copies/ml were stratified as 'below quantifiable limits' (BQL) or 'below detectable limits' (BDL). We examined the incidence of virologic relapse, defined as an HIV-1 RNA level > 400 copies/ml, for individuals with viral loads of BQL or BDL. Cox proportional hazards regression analyses were performed to control for baseline CD4 cell count, the number of antiretroviral medications, and the use of protease inhibitors (PI) and/or non-nucleoside reverse transcriptase inhibitors (NNRTI). RESULTS: Virologic relapse occurred in 52 of 168 individuals over 29,576 person-days overall (incidence rate 1.8 cases/1,000 person-days). The relapse rate was three times greater following HIV-1 RNA levels of BQL rather than BDL [crude rate ratio 3.2; 95% confidence interval (CI) 1.8-5.8]. After adjusting for baseline CD4 cell count, number of antiretroviral medications, and use of PI and/or NNRTI, the rate of relapse was nearly four times greater for individuals with HIV-1 RNA levels of BQL (hazard ratio 3.7; 95% CI 2.0-6.7). CONCLUSIONS: In a large clinic population, low-level HIV-1 RNA detected in plasma below the 400 copies/ml limit of quantifiability for Amplicor HIV-1 Monitor was associated with an increased rate of virologic relapse on therapy.

Adult↗
PubMed1999

Substrate utilization during submaximal exercise in obese and normal-weight women.

In this study we compared substrate use at submaximal intensities of a maximal graded exercise test (GXT) with that derived from equivalent intensities during continuous submaximal steady-state exercise in obese and normal-weight women. Sedentary obese (n = 20, body fat > 30%) and normal-weight (n = 15, body fat < or =30%) women performed three treadmill tests with concurrent metabolic measurements. Maximal oxygen consumption (VO2max) was determined using the Bruce protocol, followed by two, randomly assigned, continuous 15-min, steady-state exercise bouts, on different days; one bout at 50% and one bout at 75% VO2max. Analysis of variance revealed no significant differences between groups for blood lactate or respiratory exchange ratio (R) values at any point during exercise. Therefore, obese and normal-weight group data were combined for subsequent analyses. The R at 50% VO2max from the GXT [0.83 (0.01)] was significantly (P < 0.05) lower than at 8 min [0.90 (0.01)] and 15 min [0.89 (0.01)] of steady-state exercise, whereas at 75% VO2max, the GXT R [0.96 (0.01)] was similar to that seen at 8 min [0.96 (0.01)] and at 15 min of steady-state exercise [0.93 (0.01)]. Blood lactate values at 50% VO2max were similar between the GXT [1.66 (0.10) mM] and steady-state exercise [1.65 (0.09) mM], but at 75% VO2max the GXT blood lactate values [2.58 (0.21) mM] were lower than after 15 min of steady-state exercise [4.65 (0.46) mM]. Total exercise fat oxidation was greater at 50% compared to 75% VO2max. There was no difference in substrate use between sedentary obese and normal-weight women either at rest or during steady-state exercise at the same relative intensity. Total fat oxidation was greater during low- (50% VO2max) compared to high-intensity (75% VO2max) exercise. Data from a GXT cannot be used to predict R or substrate utilization values for the purpose of exercise prescription.

Adolescent↗
PubMed1999

Use of sexually transmitted disease risk assessment algorithms for selection of intrauterine device candidates.

Sexually transmitted diseases (STD) are an important contraindication for intrauterine device (IUD) insertion. Nevertheless, laboratory testing for STD is not possible in many settings. The objective of this study is to evaluate the use of risk assessment algorithms to predict STD and subsequent IUD-related complications among IUD candidates. Among 615 IUD users in Kenya, the following algorithms were evaluated: 1) an STD algorithm based on US Agency for International Development (USAID) Technical Working Group guidelines: 2) a Centers for Disease Control and Prevention (CDC) algorithm for management of chlamydia; and 3) a data-derived algorithm modeled from study data. Algorithms were evaluated for prediction of chlamydial and gonococcal infection at 1 month and complications (pelvic inflammatory disease [PID], IUD removals, and IUD expulsions) over 4 months. Women with STD were more likely to develop complications than women without STD (19% vs 6%; risk ratio = 2.9; 95% CI 1.3-6.5). For STD prediction, the USAID algorithm was 75% sensitive and 48% specific, with a positive likelihood ratio (LR+) of 1.4. The CDC algorithm was 44% sensitive and 72% specific, LR+ = 1.6. The data-derived algorithm was 91% sensitive and 56% specific, with LR+ = 2.0 and LR- = 0.2. Category-specific LR for this algorithm identified women with very low (< 1%) and very high (29%) infection probabilities. The data-derived algorithm was also the best predictor of IUD-related complications. These results suggest that use of STD algorithms may improve selection of IUD users. Women at high risk for STD could be counseled to avoid IUD, whereas women at moderate risk should be monitored closely and counseled to use condoms.

Adult↗
PubMed1999

How effective are traditional dietary and exercise interventions for weight loss?

Health care professionals have used restrictive dieting and exercise intervention strategies in an effort to combat the rising prevalence of obesity in affluent countries. In spite of these efforts, the prevalence of obesity continues to rise. This apparent ineffectiveness of diet and exercise programming to reduce obesity has caused many health care providers, obesity researchers, and lay persons to challenge the further use of diet and exercise for the sole purpose of reducing body weight in the obese. The purposes of this paper were to examine the history and effectiveness of diet and exercise in obesity therapy and to determine the best future approach for health promotion in the obese population. A brief survey of the most popular dieting techniques used over the past 40 yr shows that most techniques cycle in and out of popularity and that many of these techniques may be hazardous to health. Data from the scientific community indicate that a 15-wk diet or diet plus exercise program produces a weight loss of about 11 kg with a 60-80% maintenance after 1 yr. Although long-term follow-up data are meager, the data that do exist suggest almost complete relapse after 3-5 yr. The paucity of data provided by the weight-loss industry has been inadequate or inconclusive. Those who challenge the use of diet and exercise solely for weight control purposes base their position on the absence of weight-loss effectiveness data and on the presence of harmful effects of restrictive dieting. Any intervention strategy for the obese should be one that would promote the development of a healthy lifestyle. The outcome parameters used to evaluate the success of such an intervention should be specific to chronic disease risk and symptomatologies and not limited to medically ambiguous variables like body weight or body composition.

Calorimetry↗