Biomedical subjects

R A DeMasi

Publications and source records attributed to R A DeMasi.

10 recordsLinked to original sources

PubMed2000

Health-related quality of life and virologic outcomes in an HIV clinic.

OBJECTIVE: The purpose of this study was to describe the relationship between viral load and health-related quality of life (HRQOL) in a cohort of persons with human immunodeficiency virus (HIV) infection. DESIGN: We evaluated HRQOL measurements in a clinical cohort of HIV-positive patients recruited from a university-associated HIV primary care clinic. HRQOL instruments included the medical outcomes survey-short form-36(MOS-SF-36) from which mental and physical component summary scores (MCS and PCS) and subscale scores were calculated. RESULTS: Significant negative associations were found between viral load and SF-36 PCS, physical functioning (PF), role-physical (RP), bodily pain (BP), general health (GH), role-emotional (RE), and vitality (VT). Similar negative associations were found between CD4 cell count and SF-36 summary and subscale scores, with the notable exception of bodily pain. Multivariate analyses controlling for the effects of CD4 cell count and other clinical variables indicated viral load as an independent predictor of SF-36 PCS, RP, BP and VT scores. CONCLUSIONS: The relationship between viral load, a measure of HIV disease activity, and several dimensions of the SF-36, a patient-focused measure of HRQOL, appears to be strong and independent of CD4 cell count. These findings suggest that having a lower viral load positively impacts the quality of life of HIV-positive patients.

Adult↗

PubMed1999

Empirical power for distribution-free tests of incomplete longitudinal data with applications to AIDS clinical trials.

The design of AIDS clinical trials is of growing importance. These studies tend to be longitudinal and typically involve missing data. HIV-1 RNA is a common endpoint for these studies and is inherently non-normal, although viral load can be measured only within certain bounds, resulting in censored data. We compared several analysis methods, both univariate and multivariate, on the basis of empirical power and provide an illustrative example of data from a controlled clinical trial. Simulated viral load data demonstrate that methods adjusting for baseline data have power increasing with increasing positive intrasubject correlation expected with this type of data. Several summary measures considered have power compatible with multivariate tests.

Acquired Immunodeficiency Syndrome↗

PubMed1998

Statistical methodology for screening studies with qualitative/quantitative mixtures.

A statistical method for designing screening studies involving several experimental treatments compared to a standard treatment is developed. The screening study identifies the most promising experimental treatments, which then undergo more rigorous evaluation in a future, larger study. The technique is especially relevant for biopharmaceutical research and development in which phase II clinical trials are conducted to identify the most promising drug regimens, which then move on to phase III of clinical development. It is assumed that the underlying distribution of the primary efficacy random variable is a qualitative/quantitative mixture. The proposed methodology involves calculating the probability of accepting each experimental treatment compared to the standard treatment, where the criterion for acceptance is based on the proportion of qualitative observations and a measure of their location. The probability of acceptance is displayed in two dimensions using operating characteristic contour plots. The techniques are illustrated with some practical examples and some extensions are indicated.

Algorithms↗

PubMed1993

Knee flexor-extensor strength in children.

Isokinetic measurements of knee flexion extension in children and adolescents are a useful means of quantifying strength. In the routine clinical situation with a unilateral problem, evaluation of the affected extremity is usually based on comparisons with the unaffected side. To interpret these results, there must be an appreciation for normal side-to-side differences. Twenty-one normal, healthy children (ages 6-16 years) were evaluated using a Cybex II isokinetic dynamometer at 90 and 240 degrees/sec. In children who were able to generate peak torque values greater than 50 ft-lbs, the side-to-side differences in peak torque averaged 11 +/- 12% (mean +/- SD). A similar amount of variability has been reported with adults. For children with whom peak torque values were less than 50 ft-lbs, the side-to-side differences were much greater (mean = 22 +/- 19%). The stronger leg was equally likely to be on the nondominant side as the dominant side. Side-to-side variability was slightly decreased if the mean of several repetitions was used for comparisons rather than comparing just the single highest peak torque values.

Adolescent↗

PubMed1991

Effect of race and gender on neurological level in myelomeningocele.

The association of race and gender with different neurological levels of myelomeningocele was studied in 251 patients. Over-all, the white to black ratio was 3.6 and the male to female ratio was 0.86. However, the proportions of whites and females were significantly increased in thoracic-level patients (white to black ratio 13.6, male to female ratio 0.43), whereas the lumbar-level patients had sex and white to black ratios equivalent to the area population. This supports the concept that thoracic-level myelomeningocele has a different pathogenesis from lumbar-level.

Black People↗

PubMed1990

Update on the use of distal radial bone density measurements in prediction of hip and Colles' fracture risk.

A controversy has developed around the question as to whether bone density values from the distal radius can be used to accurately predict risk of future fractures. To address this question, two separate studies were undertaken: (a) Bone density was measured in 460 healthy ambulatory women living in retirement centers in the state of North Carolina; 83% of these women were followed for up to 60 months for occurrence of minimal trauma hip and wrist fractures. Thirty-one minimal trauma fractures were reported in our study population, representing 8% of those followed. The fracture incidence density rate showed a close inverse relationship with incremental changes in bone density at the distal site. Twenty-eight of the 31 fractures were reported in women with bone density values below the 325-mg/cm2 "at risk" value. (b) Bone density values of the distal radius and the lumbar spine from 360 women (aged 18-85 years) from the Chapel Hill area were used to analyze the error in predicting individual spinal density from the distal radial density. Although the overall correlation was high (r = 0.67) and the confidence intervals were narrow, the prediction intervals were quite wide. Thus, prediction of an individual value of spine density from the distal radius density would result in a value with a range too wide to be clinically useful. We conclude that single-photon absorptiometry appears to be a useful tool for screening normal populations of asymptomatic women for prediction of hip or Colles' fracture risk even though it has limited usefulness in prediction of spinal fracture risk or individual values for spinal density.

Aged↗

PubMedDate not supplied

Correlation between self-reported adherence to highly active antiretroviral therapy (HAART) and virologic outcome.

The Patient Medication Adherence Questionnaire Version 1.0 (PMAQ-V1.0) is a patient-reported adherence instrument to assess medication-taking behaviors and identify barriers to adherence with antiretroviral therapy. To assess the correlation between adherence and virologic outcome, the PMAQ-V1.0 was administered to 194 antiretroviral-experienced adults with HIV infection enrolled in a 16-week evaluation of protease inhibitor-containing regimens featuring a lamivudine/zidovudine combination tablet. At baseline, plasma HIV-1 RNA levels were less than 10,000 copies/mL and CD4(+)-cell counts were equal to or greater than 300 x 10(6)/L; patients had been receiving a conventional regimen of lamivudine + zidovudine (separately) plus a protease inhibitor for at least 10 weeks immediately prior to the study. Forty-eight percent of patients who reported missing at least one dose of a nucleoside reverse-transcriptase inhibitor (NRTI) during the study had detectable plasma HIV-1 RNA, compared with 26% of patients who reported no missed doses (P = .002). Patients who missed at least one dose of an NRTI or protease inhibitor were 2.5 times more likely to have quantifiable HIV-1 RNA than those who reported no missed doses. Patients who reported fewer barriers and more motivators to adherence had better virologic outcomes (P = .001). Several dimensions of the PMAQ-V1.0 did not function as well as hypothesized. In this study, self-reported adherence derived from the PMAQ-V1.0 predicted virologic outcomes, but further refinement of the dimensions appears warranted.

AIDS Serodiagnosis↗

PubMedDate not supplied

Postarthroscopy analgesia with bupivacaine. A prospective, randomized, blinded evaluation.

The analgesic effect of intraarticular bupivacaine injected at the conclusion of knee arthroscopy done under general anesthesia was investigated in a prospective, randomized, and blinded fashion. Pain scores, the use of analgesic medications, crutch use, weight-bearing, activity level, and difficulty sleeping the night after surgery were all unaffected by the use of bupivacaine. The apparent lack of effect is most likely due to rapid clearance from the knee, leaving only a transient, 1 to 2 hours of potential benefit. In this study, the patients were already quite comfortable during this time period due to the routine use of intraoperative narcotics. The preoperative level of knee discomfort was found to be a major determinant of postoperative discomfort. Other much less important factors were synovial and chondral shaving, sex of the patient, and experience of the surgeon.

Adult↗

PubMedDate not supplied

An evaluation of pre- and postoperative nonsteroidal antiinflammatory drugs in patients undergoing knee arthroscopy. A prospective, randomized, double-blinded study.

The potential benefits of a nonsteroidal antiinflammatory drug to 67 patients undergoing knee arthroscopy were evaluated in a prospective, randomized, placebo-controlled, double-blinded study. Group A received the drug (diclofenac, 75 mg twice daily) for 3 to 5 days before and for 7 days after surgery. Group B received a placebo preoperatively and the drug postoperatively. Group C received a placebo at both times. Codeine was available postoperatively for all patients if needed. Outcomes reported by the subjects included pain, crutch use, and return to activities. Outcomes assessed by physicians included knee effusion, range of motion, and gait. Knee flexion and extension strengths were measured isokinetically pre- and postoperatively. Pain scores on the 1st postoperative day were higher in Group C than in Group A. Pain scores at all other time points were not significantly different in the three treatment groups. Groups A and B required less codeine during the first 72 hours after surgery than Group C (mean, 2.9 +/- 1.0 versus 6.8 +/- 1.0 pills). Recovery of function, recovery of strength, and physical examination parameters were not significantly different in the three treatment groups. Diclofenac was an effective analgesic in the immediate postoperative period. Recovery from arthroscopy, however, was not enhanced by taking the drug.

Adolescent↗

PubMedDate not supplied

Variability in radiographic measurement of bowleg deformity in children.

The tibial metaphyseal-diaphyseal (MD) and tibial-femoral (TF) angles were measured on the radiographs of 33 knees in young children (aged 12-36 months) with bowleg deformity. Four observers of differing experience measured the films in a blinded fashion to determine the intraobserver and interobserver variability of these measurements. The clinical implications of these variabilities are described. Very little instruction and experience is necessary to make these measurements correctly and precisely. Measurement of the MD angle was superior to measurement of the TF angle. Contrary to published opinion, rotation can have a small but potentially significant effect on the measured MD angle.

Anthropometry↗