Biomedical subjects

Kim Hawkins

Publications and source records attributed to Kim Hawkins.

6 recordsLinked to original sources

PubMed2006

Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial.

OBJECTIVE: To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. DESIGN: Pragmatic, open, multicentre, randomised controlled trial. SETTING: 11 hospitals in six NHS trusts. PARTICIPANTS: 1972 people admitted to hospital as acute or elective patients. INTERVENTIONS: Participants were randomised to an alternating pressure mattress (n = 982) or an alternating pressure overlay (n = 990). MAIN OUTCOME MEASURES: The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability. RESULTS: Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval--2.3% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02). CONCLUSION: No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer. TRIAL REGISTRATION: ISRCTN 78646179.

Adult↗

PubMed2006

Pressure relieving support surfaces (PRESSURE) trial: cost effectiveness analysis.

OBJECTIVE: To assess the cost effectiveness of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers in patients admitted to hospital. DESIGN: Cost effectiveness analysis carried out alongside the pressure relieving support surfaces (PRESSURE) trial; a multicentre UK based pragmatic randomised controlled trial. SETTING: 11 hospitals in six UK NHS trusts. PARTICIPANTS: Intention to treat population comprising 1971 participants. MAIN OUTCOME MEASURES: Kaplan Meier estimates of restricted mean time to development of pressure ulcers and total costs for treatment in hospital. RESULTS: Alternating pressure mattresses were associated with lower overall costs (283.6 pounds sterling per patient on average, 95% confidence interval--377.59 pounds sterling to 976.79 pounds sterling) mainly due to reduced length of stay in hospital, and greater benefits (a delay in time to ulceration of 10.64 days on average,--24.40 to 3.09). The differences in health benefits and total costs for hospital stay between alternating pressure mattresses and alternating pressure overlays were not statistically significant; however, a cost effectiveness acceptability curve indicated that on average alternating pressure mattresses compared with alternating pressure overlays were associated with an 80% probability of being cost saving. CONCLUSION: Alternating pressure mattresses for the prevention of pressure ulcers are more likely to be cost effective and are more acceptable to patients than alternating pressure overlays.

Adult↗

PubMed2005

Minimization--reducing predictability for multi-centre trials whilst retaining balance within centre.

Minimization is often used to assign patients to treatment groups to ensure good balance in patient numbers within centre and other prognostic factors. Balance within centre is preferable since large imbalances between treatment arms may have logistical implications for centres, such as cost and resource implications. However, recent concern over high predictability of treatment allocation by centres when using minimization has caused this method to be questioned. We used data from current clinical trials to assess predictability and summarize subsequent within-centre imbalances with the aim of finding the most effective minimization method for reducing predictability whilst still retaining sufficient balance within centre, when randomization is to one of two treatments. We compared prediction rates and imbalances for deterministic minimization, and minimization incorporating various random elements, p (p=0.95,0.90,0.80,0.75,0.70). We also compared prediction rates and imbalance when centre was and was not included as a stratification factor. Incorporating a random element proved successful in reducing prediction rates whilst minimizing the inevitable increase in within-centre imbalance, whereas excluding centre as a stratification factor incurred major within-centre imbalance. We therefore suggest that minimization can still be used, and that centre can be included as a stratification factor, but a random element has to be incorporated into the minimization algorithm. Minimization incorporating a random element of 0.80 is the most efficient method to use based upon the simulations undertaken in this study of real clinical trial data using different probabilities of allocation.

Algorithms↗

PubMed2005

Symptoms of obstructive sleep apnea in patients with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a term often used to describe two related conditions: a relatively benign, nonalcoholic fatty liver (NAFL) and potentially aggressive, nonalcoholic steatohepatitis (NASH). Both conditions (NAFL and NASH) occur in the setting of peripheral insulin resistance. Recently, obstructive sleep apnea (OSA) has been proposed as an independent risk factor for insulin resistance. To date, few studies have documented the prevalence of OSA or symptoms of OSA (SOSA) in NAFLD patients. The objectives of this study were (1) to document the prevalence of SOSA in patients with NAFLD and (2) to determine whether prevalence rates for SOSA differ in NAFL versus NASH patients. One hundred ninety biochemically defined NAFLD patients (116 NAFL and 74 NASH), of whom 50 (18 NAFL and 32 NASH) had undergone liver biopsy, completed a Modified Berlin Sleep Apnea Questionnaire for SOSA. Risk factors for NAFLD were also documented in NAFL and NASH patients. Eighty-seven of the 190 (46%) NAFLD patients met questionnaire criteria for SOSA. The prevalence of SOSA was similar in both biochemically (45% versus 49%, respectively; P = 0.66) and histologically (39% versus 63%, respectively; P = 0.11) defined NAFL and NASH patients. Other risk factors for NAFLD such as body mass index, plasma cholesterol and triglyceride levels, and prevalence of diabetes were also similar in the two groups. Approximately one-half of NAFLD patients, whether NAFL or NASH, have SOSA. Further studies are required to determine whether a causal link exists between NAFLD and OSA.

Adult↗

PubMed2003

High-dose chemotherapy with hematopoietic stem-cell rescue for multiple myeloma.

BACKGROUND: High-dose therapy with supporting autologous stem-cell transplantation remains a controversial treatment for cancer. In multiple myeloma, first-line regimens incorporating high-dose therapy yield higher remission rates than do conventional-dose treatments, but evidence that this translates into improved survival is limited. METHODS: In this multicenter study, the Medical Research Council Myeloma VII Trial, we randomly assigned 407 patients with previously untreated multiple myeloma who were younger than 65 years of age to receive either standard conventional-dose combination chemotherapy or high-dose therapy and an autologous stem-cell transplant. RESULTS: Among the 401 patients who could be evaluated, the rates of complete response were higher in the intensive-therapy group than in the standard-therapy group (44 percent vs. 8 percent, P<0.001). The rates of partial response were similar (42 percent and 40 percent, respectively; P=0.72), and the rates of minimal response were lower in the intensive-therapy group than in the standard-therapy group (3 percent vs. 18 percent, P<0.001). Intention-to-treat analysis showed a higher rate of overall survival (P=0.04 by the log-rank test) and progression-free survival (P<0.001) in the intensive-therapy group than in the standard-therapy group. As compared with standard therapy, intensive treatment increased median survival by almost 1 year (54.1 months [95 percent confidence interval, 44.9 to 65.2] vs. 42.3 months [95 percent confidence interval, 33.1 to 51.6]). There was a trend toward a greater survival benefit in the group of patients with a poor prognosis, as defined by a high beta2-microglobulin level (more than 8 mg per liter). CONCLUSIONS: High-dose therapy with autologous stem-cell rescue is an effective first-line treatment for patients with multiple myeloma who are younger than 65 years of age.

Adult↗

PubMed2003

Evolutionary genetics of the melanocortin-1 receptor in vertebrates.

The molecular genetic basis of adaptive change in phenotype is a major outstanding issue in evolutionary biology. Evolutionary change in coat and plumage color is a promising system for making progress in this field. Most notably, recent work on the molecular genetic basis of hair and feather color has identified several genes which are candidates for involvement in evolutionary color change in mammals and birds. We have investigated the evolution of one of these candidate genes, the melanocortin-1 receptor (MC1R) gene, in relation to changes in melanin distribution among a wide variety of primate species, and in bananaquits (Coereba flaveola), which are a classic case of melanic plumage polymorphism in birds. In primates, a role of the MC1R coding region in coat color evolution can be ruled out in several cases in which closely related species have drastically different distributions of eumelanin and/or pheomelanin. However, reconstruction of MC1R sequences over primate evolution shows the presence of mutations at important functional sites in several lineages. Most notably, the lion tamarins (Leontopithecus) show a striking pattern of MC1R evolution, including deletions and several nonconservative amino acid changes. In the bananaquit, an E92K substitution in the MC1R is strongly associated with melanism, and this is likely to be the causative mutation. Reconstruction of the evolution of bananaquit MC1R alleles shows that melanism is a derived trait in this species. These results confirm the utility of a candidate gene approach to color evolution in vertebrates and open the way for extensive future research.

Animals↗