Biomedical subjects
M Hills
Publications and source records attributed to M Hills.
Missed opportunities for the prevention of cardiovascular disease among British hypertensives in primary care.
BACKGROUND: High-risk strategies for the prevention of cardiovascular disease (CVD) among hypertensive patients require knowledge of the prevalence and interaction of modifiable risk factors to ensure effective targeting of interventions. Comparatively little is known of risk-factor profiles and their modification among hypertensives in primary care. AIM: The present study was designed to explore relationships between patients' knowledge of CVD risk factors, their perception of personal risk and health behaviours, and their use of lifestyle interventions. METHOD: A cross-sectional survey of 2676 men and women with mild to moderate hypertension (diastolic blood pressure 95-115 mmHg), and their general practitioners, recruited from 1044 general practices throughout the UK, was conducted. RESULTS: Levels of modifiable risk factors were high, although there was considerable variation by age and sex; most (98.5%) patients had at least one additional CVD risk factor. A lower standard of living was associated with a higher prevalence of 'unhealthy' behaviours. Out of those with a current lifestyle problem, 85% of obese patients, 59% of smokers, 47% of excess drinkers, 49% of those with dietary risk factors and 32% of inactive patients claimed to have adopted healthier behaviours within the past 3 months. Older subjects and those with a lower standard of living were less likely to acknowledge risks, and those who did were less likely to report improving their lifestyles. While 71% of patients recalled receiving lifestyle advice, the coverage and targeting of specific interventions was generally poor. Overall, 60% of the sample had received advice on weight control, 47% on diet, 38% on exercise, 38% on smoking and 36% on alcohol. Women and older people were less likely to be given relevant counseling, and there was no evidence of targeting with respect to subjects' social class, level of hypertension or duration of diagnosis. CONCLUSION: Lifestyle interventions are welcomed and are viewed as helpful by patients receiving them. Potential health gains among high-risk hypertensives are being lost because of poor targeting and coverage of those at greatest risk.
Estimating the degree of heterogeneity between event rates using likelihood.
The observed variability between mortality or morbidity rates in epidemiologic studies is partly due to random fluctuations. The same is true for rate ratios relative to reference rates. A method for estimating the distribution of true rate ratios is applied to a data set of perinatal mortality in 515 small areas in the North West Thames Health Region, England, in the period 1986-1990. Combining the random Poisson variability with the assumption that the true rate ratios are drawn from a gamma distribution (a family of positive unimodal distributions) produces a negative binomial log-likelihood for the dispersion parameter of the gamma. The maximum likelihood estimate of this parameter and its confidence interval are then found via direct numerical methods; alternatively, the hypothesis of no heterogeneity is tested by a likelihood ratio. The standardized mortality ratios (SMRs) for the data have an empirical distribution with 5th percentile at 0 and 95th percentile at 1.92, but their true variability, as described by the 5th to 95th percentiles of the fitted gamma distribution, is from 0.72 to 1.32. The likelihood ratio test confirmed this result, rejecting the hypothesis that the true rates are homogeneous (p = 0.015). The method requires only modest computing resources and is useful when assessing the need for more detailed study.
Smoking behaviour can be predicted by neighbourhood deprivation measures.
STUDY OBJECTIVE: To assess whether small area measures of socioeconomic deprivation predict variation in individual smoking behaviour. To examine the adequacy of an individual level statistical model for the analysis of data on groups of individuals who live in the same geographical area. DESIGN: Individual level and two level logistic regression analysis of data on individual smoking from a regional health survey, and neighbourhood deprivation scores for 1991 census wards calculated from 1991 census data. SETTING: The North West Thames Regional Health Authority area. PARTICIPANTS: Random sample of 8,251 adults in North West Thames Regions. MAIN RESULTS: There was a highly significant association between being a smoker and the neighbourhood deprivation score of the area of residence. With the two level model, after allowing for age and sex, the estimated odds ratio of being a smoker for an individual in the highest quintile of deprivation compared with someone in the lowest quintile was 1.52 (95% confidence interval 1.33, 1.74). Results obtained using the individual level model were similar. Variation between wards accounted for around 6% of the total variation in smoking behaviour after neighbourhood deprivation of the ward had been taken into account. Deprivation of the area of residence remained a significant predictor of smoking status even after the socioeconomic group of the individual has been taken into account. CONCLUSIONS: Neighbourhood deprivation of the area of residence is a predictor of smoking status of individuals. In this example the two level model was reasonably well approximated by the individual level model.
Family nursing assessment: meeting the challenge of health promotion.
Family nursing assessment has traditionally followed an illness-care model. This paper proposes a re-evaluation of traditional family assessment and suggests an approach which is fundamentally based in health promotion. The paper includes a discussion of varying perspectives of health and health care, the health promotion perspective adopted by the World Health Organization, and the relevance of these perspectives for family nursing practice. Central elements of health promotion are outlined and serve as the guiding principles for family nursing assessment. Two inherent aspects of health-promoting family nursing practice are proposed and described. These include an emphasis on a human caring nursing ontology, and a framework for guiding family nursing assessment. This health-promoting assessment framework contains four essential components: (a) listening to the family; (b) participatory dialogue; (c) recognizing patterns; and (d) envisaging action and positive change. These components are described, together with the strategic elements inherent in each. Based on this health-promoting family nursing assessment, implications for nursing practice are discussed, and recommendations are made for research into this assessment framework.
Definition of human papillomavirus type 16 DNA levels in low and high grade cervical lesions by a simple polymerase chain reaction technique.
Human papillomavirus type 16 (HPV 16) is associated with a high proportion of cervical cancers and pre-cancers but has also been reported by some workers to be widely distributed in the normal population. Using a semi-quantitative polymerase chain reaction technique (PCR) operated with carefully regulated sensitivity we have established two distinct levels of HPV 16 DNA which distinguish between high and low grade cervical lesions. The potential use of such an approach in the understanding and management of HPV related cervical disease is discussed.
Time-space case clusters of Burkitt's lymphoma in Malawi.
The geographical co-ordinates of 146 cases of Burkitt's lymphoma in Malawi, with date of onset between July 1987 and October 1989, were recorded. Case clusters, pairs of cases, closer together in time and space than would be expected by chance, were discovered, using Knox's method, for children over the age of 8 years, but not for all ages.
Incidence of cancers of the larynx and lung near incinerators of waste solvents and oils in Great Britain.
The Small Area Health Statistics Unit (SAHSU) is a new independent facility for the investigation of disease near industrial installations in the UK. SAHSU analysed the incidence of cancers of the larynx and lung near the incinerator of waste solvents and oils at Charnock Richard, Coppull, Lancashire (which operated between 1972 and 1980) and nine other similar incinerators in Great Britain, after reports of a cluster of cases of cancer of the larynx near the Charnock Richard site. Postcoded cancer registration data were available for 1974-84 in England and Wales and 1975-87 in Scotland. Lag periods of 5 and 10 years were used between start-up (or first registration) of the incinerators and cancer incidence. Standardised observed/expected (O/E) ratios were assessed within 3 km and 3-10 km of each site and then aggregated over all sites. Expected values were based on national rates (regionally adjusted) with and without stratification by Carstairs' index, a measure of the socioeconomic profile of areas that uses census data for enumeration districts. Data were also assessed over a range of circles up to 10 km to test for trend in O/E ratios with distance. For Charnock Richard, none of the O/E ratios within 3 km or from 3-10 km differed significantly from unity, for either cancer or lag period. In the analysis of all sites with stratification by Carstairs' index, none of these O/E ratios differed significantly from unity for the two cancers. There was no evidence of decreasing risk with distance from the sites of either cancer. We conclude that the apparent cluster of cases of cancer of the larynx reported near Charnock Richard was unlikely to be due to its former incinerator.
The Small Area Health Statistics Unit: a national facility for investigating health around point sources of environmental pollution in the United Kingdom.
STUDY OBJECTIVE: The Small Area Health Statistics Unit (SAHSU) was established at the London School of Hygiene and Tropical Medicine in response to a recommendation of the enquiry into the increased incidence of childhood leukaemia near Sellafield, the nuclear reprocessing plant in West Cumbria. The aim of this paper was to describe the Unit's methods for the investigation of health around point sources of environmental pollution in the United Kingdom. DESIGN: Routine data currently including deaths and cancer registrations are held in a large national database which uses a post code based retrieval system to locate cases geographically and link them to the underlying census enumeration districts, and hence to their populations at risk. Main outcome measures were comparison of observed/expected ratios (based on national rates) within bands delineated by concentric circles around point sources of environmental pollution located anywhere in Britain. MAIN RESULTS: The system is illustrated by a study of mortality from mesothelioma and asbestosis near the Plymouth naval dockyards during 1981-87. Within a 3 km radius of the docks the mortality rate for mesothelioma was higher than the national rate by a factor of 8.4, and that for asbestosis was higher by a factor of 13.6. CONCLUSIONS: SAHSU is a new national facility which is rapidly able to provide rates of mortality and cancer incidence for arbitrary circles drawn around any point in Britain. The example around Plymouth of mesothelioma and asbestosis demonstrates the ability of the system to detect an unusual excess of disease in a small locality, although in this case the findings are likely to be related to occupational rather than environmental exposure.
An analysis of the concept of hardiness.
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Serial studies on the evolution of drug resistance in malaria in an area of east Africa: findings from 1979 up to 1986.
Observations, previously reported for 1979-82, have been continued up to 1986 on the development of drug resistance in P. falciparum in the North Mara area of Tanzania, where a chloroquine chemosuppression campaign was attempted from 1977 to 1982. The WHO micro in-vitro test for chloroquine and other drugs was used. Because of the large number of tests done, each test was characterized by the mean minimum inhibitory concentrations (MIC) of drug needed to prevent schizont development instead of counting the numbers of schizonts. The MIC for chloroquine has risen progressively each year but changes in the findings of in-vivo tests were less dramatic possibly due to the effects of immunity. Resistance to amodiaquine has followed that to chloroquine at a lower level, and in the last years the MIC for quinine has risen. Sporadic resistance to mefloquine was found and, by in-vivo test, to sulphadoxine-pyrimethamine. Possible factors in the evolution of drug resistance are discussed together with implications for the future.
The molluscicidal properties of Ambrosia maritima L. (Compositae). 3. A comparative field trial using dry and freshly-harvested plant material.
A comparative trial of freshly-harvested and dry forms of the plant molluscicide, Ambrosia maritima is described. The plant was grown near Alexandria, Egypt and gave a weight ratio of 4:1 for fresh: dry, mature plants. Applications of plant material were made to irrigation watercourses at dosage levels of 560 mg . l-1 fresh and 70 and 140 mg . l-1 dry in May and 280 mg . l-1 fresh and 70 mg . l-1 dry in June. Snail numbers were reduced to low levels after two weeks in all treatments. Statistically significant differences could not be detected between the molluscicidal effects of fresh and dry material or their use in May and June. The cultivated plant has a similar order of activity to that collected from the wild. The snail number reduction was maintained to the end of the year in all treatments. This confirms an earlier finding that a correctly-timed, single application of the plant is capable of controlling snails throughout the entire schistosomiasis transmission season in Lower Egypt.
Fire department sets example for respiratory protection evaluation.
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The allometry of relative cusp size in hominoid mandibular molars.
The crown area (MCBA) and cusp areas of mandibular molars of Homo sapiens (M-1 = 131; M-2 = 71), Gorilla (M-1 = 25) and Pongo (M-1 = 24) were studied to determine whether the relative size of the mesial and distal cusps are related to overall crown size. Allometric trends were assessed by examining the correlation between relative cusp areas and MCBA and by calculating the slope of the regression line of log cusp area and log MCBA. With the exception of the metaconid in the Homo sapiens M-2S, the results of the intraspecific analyses provide little evidence of an allometric trend for relative reduction of the mesial cusps with increasing crown size. None of the samples provide consistent or reliable evidence of such a trend for the protoconid, nor do the M-1 samples provide evidence for such a trend for the metaconid. The evidence from the distal cusps is also mixed: positive allometry for the entoconid for the Homo sapiens M-2S and for the hypoconulid for the Homo sapiens M-1S, with no departure from isometry in either Gorilla or Pongo. The interspecific data provide no evidence of any trend for the mesial cusps to decrease or the distal cusps to increase in importance in larger teeth. If one accepts the proposition that the static allometric trends observed in this study are reasonable analogues for any allometric relationships within, or between, fossil hominid taxa, then the evidence presented above does not support the hypothesis that the reduction of the trigonid, which is observed in the "robust" australopithecines, is an allometric phenomenon.
The two-period cross-over clinical trial.
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The prothrombin time test: effect of varying citrate concentration.
Blood samples from 12 normal subjects and 46 patients on oral anticoagulants were divided so that each was anticoagulated with four concentrations of trisodium citrate solution in the range 0.09-0.15 M, 9 vol blood being added to 1 vol citrate solution in each case. Citrated blood haematocrit and plasma prothrombin time was measured on each subsample; 0.025 M CaCl2-solution was used for recalcification throughout. Three laboratories participated, each using a different prothrombin-time technique.
Reference method for the one-stage prothrombin time test on hlman blood. International committee for standardization in hematology.
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Proceedings: ICSH-ISTH International Anticoagulant Control Study. II. Design and findings.
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