PubMed Health⌕ Search

Biomedical subjects

Michael Power

Publications and source records attributed to Michael Power.

11 recordsLinked to original sources
PubMed2006

Evaluating common de-identification heuristics for personal health information.

BACKGROUND: With the growing adoption of electronic medical records, there are increasing demands for the use of this electronic clinical data in observational research. A frequent ethics board requirement for such secondary use of personal health information in observational research is that the data be de-identified. De-identification heuristics are provided in the Health Insurance Portability and Accountability Act Privacy Rule, funding agency and professional association privacy guidelines, and common practice. OBJECTIVE: The aim of the study was to evaluate whether the re-identification risks due to record linkage are sufficiently low when following common de-identification heuristics and whether the risk is stable across sample sizes and data sets. METHODS: Two methods were followed to construct identification data sets. Re-identification attacks were simulated on these. For each data set we varied the sample size down to 30 individuals, and for each sample size evaluated the risk of re-identification for all combinations of quasi-identifiers. The combinations of quasi-identifiers that were low risk more than 50% of the time were considered stable. RESULTS: The identification data sets we were able to construct were the list of all physicians and the list of all lawyers registered in Ontario, using 1% sampling fractions. The quasi-identifiers of region, gender, and year of birth were found to be low risk more than 50% of the time across both data sets. The combination of gender and region was also found to be low risk more than 50% of the time. We were not able to create an identification data set for the whole population. CONCLUSIONS: Existing Canadian federal and provincial privacy laws help explain why it is difficult to create an identification data set for the whole population. That such examples of high re-identification risk exist for mainstream professions makes a strong case for not disclosing the high-risk variables and their combinations identified here. For professional subpopulations with published membership lists, many variables often needed by researchers would have to be excluded or generalized to ensure consistently low re-identification risk. Data custodians and researchers need to consider other statistical disclosure techniques for protecting privacy.

Biomedical Research↗
PubMed2006

Buying Time I: a prospective, controlled trial of a joint health/social care residential rehabilitation unit for older people on discharge from hospital.

The study's objective was to determine the effectiveness of a joint NHS/Social Services rehabilitation unit (a form of intermediate care) for older people on discharge from community hospital, compared with 'usual' community services. This was a controlled clinical trial in a practice setting. The intervention was 6 weeks in a rehabilitation unit where individuals worked with care/rehabilitation assistants and occupational therapists to regain independence. Controls went home with the health/social care services they would ordinarily receive. Participants were from two matched geographical areas in Devon: one with a rehabilitation unit, one without. Recruitment was from January 1999 to October 2001 in 10 community hospitals. Study eligibility was assessed using the unit's inclusion/exclusion criteria: 55 years or older and 'likely to benefit from a short-term rehabilitation programme' ('potential to improve', 'realistic and achievable goals' and 'motivation to participate'). Ninety-four people were recruited to the intervention and 112 to the control. The mean (standard deviation) age was 81.8 (8.0) years. The main outcome measure was prevention of institutionalisation assessed by the number of days from baseline interview to admission to residential/nursing care or death ('survival-at-home time'). Secondary outcome measures were time to hospital re-admission over 12 months, quality of life and coping ability. There were no significant differences between the groups on any outcome measure. Adjusted hazard ratio (95% CI) for 'survival-at-home time' was 1.13 (0.70-1.84), and 0.84 (0.53-1.33) for 'time to hospital re-admission'. However, attending the unit was associated with earlier hospital discharge. Median (interquartile range) days in hospital for the intervention graph was 27 (20, 40), and for the control graph was 35 (22, 47) (U = 4234, P = 0.029). These findings suggest a stay in a rehabilitation unit is no more effective than 'usual' care at diverting older people from hospital/long-term care. Alternative service configurations may be as effective, having implications for tailoring services more specifically to individual need and/or user preferences. However, the unit did appear to facilitate earlier discharges from community hospital.

Aged↗
PubMed2006

Buying time II: an economic evaluation of a joint NHS/Social Services residential rehabilitation unit for older people on discharge from hospital.

The study's aim was to investigate the cost-effectiveness of an NHS/Social Services short-term residential rehabilitation unit (a form of intermediate care) for older people on discharge from community hospital compared with 'usual' community services. An economic evaluation was conducted alongside a prospective controlled trial, which explored the effectiveness of a rehabilitation unit in a practice setting. The aim of the unit was to help individuals regain independence. A matched control group went home from hospital with the health/social care services they would ordinarily receive. The research was conducted in two matched geographical areas in Devon: one with a rehabilitation unit, one without. Participants were recruited from January 1999 to October 2000 in 10 community hospitals and their eligibility determined using the unit's strict inclusion/exclusion criteria, including 55 years or older and likely to benefit from a short-term rehabilitation programme: potential to improve, realistic, achievable goals, motivation to participate. Ninety-four people were recruited to the intervention and 112 to the control group. Details were collated of the NHS and Social Services resources participants used over a 12-month follow-up. The cost of the resource use was compared between those who went to the unit and those who went straight home. Overall, costs were very similar between the two groups. Aggregated mean NHS/Social Services costs for the 12 months of follow-up were pound 8542.28 for the intervention group and pound 8510.68 for the control. However, there was a clear 'seesaw' effect between the NHS and Social Services: the cost of the unit option fell more heavily on Social Services (pound 5011.56, whereas pound 3530.72 to the NHS), the community option more so on the NHS (pound 5146.74, whereas pound 3363.94 to Social Services). This suggests that residential rehabilitation for older people is no more cost-effective over a year after discharge from community hospital than usual community services. The variability in cost burden between the NHS and Social Services has implications for 'who pays' and being sure that agencies share both pain and gain.

Aged↗
PubMed2004

Endocrine changes in full-term pregnancies and pregnancy loss due to energy restriction in the common marmoset (Callithrix jacchus).

Common marmosets, a New World primate, respond to a modest energy restriction with early termination of the pregnancy. Within female marmosets, comparisons (n = 6) between a normal, term pregnancy and a restriction-induced aborted pregnancy were used to establish cortisol, free estradiol, and chorionic gonadotropin (CG) as urinary markers of placental and fetal function under these two conditions. Abortions occurred 11-47 d after a 25% energy reduction during midpregnancy for all females. Cortisol concentrations were significantly lower in the last 2 wk for the restricted pregnancy than for matched samples in the normal term pregnancy. Both estradiol and estrone were examined in free and conjugated forms. Only free estradiol showed a significant reduction in mean concentrations during midpregnancy for the restricted females compared with their normal, term pregnancies. Mean CG levels from each female served as an independent marker of placental differentiation and function. CG levels were significantly lower during the 2 wk before abortion compared with matched days from a normal, term pregnancy. These data provide evidence that estradiol and cortisol are useful markers of placental and fetal viability in the common marmoset, and their reduced concentration following energy restriction suggests that restriction is not acting as a classical stressor by increasing cortisol and, subsequently, estradiol concentration.

Abortion, Spontaneous↗
PubMed2004

Energy restriction initiated at different gestational ages has varying effects on maternal weight gain and pregnancy outcome in common marmoset monkeys (Callithrix jacchus).

With relatively high fertility and short lifespan, marmoset monkeys (Callithrix jacchus) may become useful primate models of prenatal nutritional effects on birth condition and adult disease risk. The present study determined the effects of energy restriction to 75% of expected ad libitum consumption during mid- (day 66) or late (day 99) gestation on maternal weight, fetal growth and pregnancy outcomes in this species. Mid-restriction reliably induced the loss of pregnancy before term, at 92 d, on average. Of the late-restricted pregnancies, four of seven were normal term length while three were preterm deliveries, at 101, 117 and 132 d. Control females had a mean mid-pregnancy weight gain of 0.67 g/d while mid-restricted females lost -0.65 g/d, on average. Control pregnancies averaged a 1.06 g/d gain during late pregnancy, while energy-restricted females lost -0.67 g/d, on average. Restriction-related weight change was highly variable, ranging from +0.55 to -2.56 g/d for mid-restriction pregnancies and from +0.79 to -3.91 g/d for late-restriction pregnancies. For mid-restriction pregnancies, the number of restriction days was best explained by linear weight change and total weight loss while the number of restriction days in late pregnancy was best explained by linear weight change alone. In late-restriction pregnancies, smaller females had higher daily weight losses. Restrictions did not induce litter-size reduction or growth restriction in those infants that were delivered at term but the size of aborted fetuses suggested that at least some pregnancies lost preterm may have involved impaired intra-uterine growth.

Animals↗
PubMed2004

Fish host-cestode parasite stable isotope enrichment patterns in marine, estuarine and freshwater fishes from Northern Canada.

Cestode parasites from freshwater (threespine stickleback, Gasterosteus aculeatus), estuarine (brook charr, Salvelinus fontinalis) and marine (Greenland cod, Gadus ogac) fish from northern Quebec, Canada, were used to investigate the hypotheses that cestode parasites are (13)C and (15)N enriched relative to host food sources, but (15)N depleted with respect to host muscle tissue as a result of differential enrichment during the assimilation of common nutrient sources. Cestode parasites and fish were generally similarly enriched in (13)C with respect to common food sources and, in the case of Greenland cod, cestode parasites were (13)C enriched relative to host tissue. Cestode parasites were also generally (15)N enriched with respect to mean host dietary signatures, but depleted with respect to host muscle tissue. In the case of Greenland cod cestode parasites, no significant (15)N enrichment relative to host dietary signature was observed. Cestode parasites appear generally to experience smaller (15)N enrichment than hosts as a result of trophic transfer of common dietary sources. Differential (15)N enrichment patterns in parasites and fish may be attributed to differences in parasite and host metabolism, particularly the anaerobic and aerobic natures of their respective metabolisms. Results imply that isotope enrichment paradigms developed for the study of aquatic foodwebs cannot be routinely applied to quantitatively assess the role of parasites in aquatic foodwebs and that reference to host muscle tissue measures will not allow accurate characterization of parasite foodweb position. Appropriate reference to assimilated food sources is required to accurately estimate parasite isotopic enrichment patterns and to determine parasite trophic position relative to the host.

Animals↗
PubMed2003

Randomized controlled trial of an early discharge rehabilitation service: the Belfast Community Stroke Trial.

BACKGROUND AND PURPOSE: To compare a community-based multidisciplinary stroke team (CST) approach with hospital-based rehabilitation in terms of hospital stay, functioning, quality of life, and service use and costs. METHODS: Stroke patients who met pre-agreed criteria were allocated randomly to the CST service (n=59) or to usual inpatient rehabilitation and follow-up care (n=54). Assessments were completed at randomization and 12 months later. Caregiver strain and satisfaction (n=55) were also assessed. Cost data were collected for a subsample of 38 patients. RESULTS: Almost 80% of surviving patients (n=691) were discharged home and a small number (n=55) were readmitted. Approximately 17% (113/649) were randomized. There were no statistically significant differences in hospital duration, costs, or outcome measures at baseline and 12 months except for higher satisfaction reported by CST patients. Overall, both groups recorded improvement in most domains over time. Carers reported a high level of satisfaction although the level of strain among carers is cause for concern. The community group (n=18) cost less than the hospital group (n=20). CONCLUSIONS: A mixed model of hospital-based and community-based rehabilitation services is likely to lead to increased patient choice and satisfaction and a potential reduction in bed pressures for less severe stroke patients.

Caregivers↗
PubMed2002

Climatic influence on a marine fish assemblage.

Understanding the fluctuations in marine fish stocks is important for the management of fisheries, and attempts have been made to demonstrate links with oceanographic and climatic variability, including the North Atlantic Oscillation (NAO). The NAO has been correlated with a range of long-term ecological measures, including certain fish stocks. Such environmental influences are most likely to affect susceptible juveniles during estuarine residency, as estuaries are critical juvenile nursery or over-wintering habitats. Here we show that, during a 16-year period, climatic forcing (by means of the NAO) is consistently the most important parameter explaining variation in assemblage composition, abundance and growth of juvenile marine fish during estuarine residency. A possible mechanism for the effect of the NAO is a temperature differential between estuarine and marine waters that allows fish to facultatively exploit optimal thermal habitats. The connection has potentially important implications for the size and numbers of individuals recruited to the fishery, for understanding and predicting the composition of juvenile fish stocks using estuaries, and for the appropriate conservation of estuarine systems in relation to fish stocks.

Animals↗
PubMed2002

A toolkit to facilitate the implementation of clinical practice guidelines in healthcare settings.

In the early stages of development and pilot implementation of the guidelines, it became apparent that organizations were struggling to identify ways to introduce and implement the guidelines. The majority of the pilot sites were providing education sessions to facilitate CPG utilization with little attention to other implementation strategies. Those charged with introducing the CPG into the clinical setting were soon faced with a myriad of implementation challenges for which they needed a solution. It became clear that a planned systematic approach to facilitate implementation of CPGs was needed.

Canada↗
PubMedDate not supplied

Early supported discharge services for stroke patients: a meta-analysis of individual patients' data.

BACKGROUND: Stroke patients conventionally undergo a substantial part of their rehabilitation in hospital. Services have been developed that offer patients early discharge from hospital with rehabilitation at home (early supported discharge [ESD]). We have assessed the effects and costs of such services. METHODS: We did a meta-analysis of data from individual patients who took part in randomised trials that recruited patients with stroke in hospital to receive either conventional care or any ESD service intervention that provided rehabilitation and support in a community setting with the aim of shortening the duration of hospital care. The primary outcome was death or dependency at the end of scheduled follow-up. FINDINGS: Outcome data were available for 11 trials (1597 patients). ESD services were mostly provided by specialist multidisciplinary teams to a selected group (median 41%) of stroke patients admitted to hospital. There was a reduced risk of death or dependency equivalent to six (95% CI one to ten) fewer adverse outcomes for every 100 patients receiving an ESD service (p=0.02). The hospital stay was 8 days shorter for patients assigned ESD services than for those assigned conventional care (p<0.0001). There were also significant improvements in scores on the extended activities of daily living scale and in the odds of living at home and reporting satisfaction with services. The greatest benefits were seen in the trials evaluating a coordinated multidisciplinary ESD team and in stroke patients with mild to moderate disability. INTERPRETATION: Appropriately resourced ESD services provided for a selected group of stroke patients can reduce long-term dependency and admission to institutional care as well as shortening hospital stays.

Activities of Daily Living↗