PubMed HealthSearch

Biomedical subjects

D Jenkinson

Publications and source records attributed to D Jenkinson.

10 recordsLinked to original sources

The distribution of peak expiratory flow variability in a population sample.

Although serial peak expiratory flow (PEF) measurements are often used to assess the variability of airflow obstruction, the range of values to be expected in the general population has never been defined, nor is there any consensus as to how PEF variability should be expressed. We have compared PEF recordings made by 121 subjects selected at random from the population of a small town (Group A) and 221 subjects selected because of wheeze in the last year (Group B). Subjects were asked to record PEF every 2 h during waking hours for 7 days using a mini-Wright peak flow meter. Seven indices of PEF variability were derived for each subject and the range for each index determined. All indices showed a positively skewed distribution in the random sample. Two variability indices, standard deviation percent mean and amplitude percent mean, provided the greatest separation between subjects with both a diagnosis of asthma and wheeze in the last year and subjects with neither feature and also provided the highest intra-class correlation coefficients. We conclude that amplitude percent mean and standard deviation percent mean provide the best means of expressing PEF variability for epidemiological purposes, but that amplitude percent mean is more easily derived and appears to be the index of choice. PEF variability has a continuous distribution in the general population and no clear-cut division between asthmatic and nonasthmatic subjects can be defined.

Adolescent

Comparison of effects of a self management booklet and audiocassette for patients with asthma.

The effects on self management of asthma of a specially prepared book and audiocassette tape with similar contents were observed in a controlled study of 177 patients with asthma in general practice. After a run in period of six months patients were randomly given the book, the tape, both the book and tape, or neither. Patients' knowledge of the use of drugs, perceptions of their disability, skill in using an inhaler, consumption of drugs, consultations with their general practitioners, morbidity (from patients' entries on diary cards), and use of the educational material were measured. Knowledge about the use of drugs was significantly increased in the groups who received the material after three months and persisted after 12 months. Patients who had been given the tape or the book and tape increased their scores of knowledge of drugs more than patients given the book alone. Patients in all groups given the material considered that their disability was reduced. There were no other significant changes. Patients given both the book and the tape preferred the book. Patients with asthma can obtain useful information from such material. The paradoxical result whereby patients learnt more from the tape but preferred the book suggests that a distinction can be made between information that patients need, which may be acquired better from an audiocassette, and information that they want, which may be acquired better from a book.

Asthma

Duration of effectiveness of pertussis vaccine: evidence from a 10 year community study.

A 10 year study of whooping cough in a discrete general practice community was performed to assess longitudinally the efficacy of pertussis vaccine from one to seven years after immunisation. Of the 436 cases of whooping cough over 10 years, 326 occurred in children aged 1-7 years. The rate of immunisation was known for each cohort of children born during each year, and the attack rate of whooping cough was thus calculated for those immunised and unimmunized. The attack rates were highest in those cohorts exposed to the epidemics of 1977-9, 1981-3, and 1985-7. The efficacy of the vaccine was calculated as a percentage as (attack rate in unimmunized group--attack rate in immunised group) x 100/attack rate in unimmunized group. It fell from 100% in the first year to 46% in the seventh, being 84% in the fourth and only 52% in the fifth. Thus the pertussis vaccine or its schedule of use does not seem to provide sufficient herd immunity to prevent outbreaks of whooping cough. Matters might be improved if vaccination against pertussis were included in the preschool immunisation programme.

Child

A search for subclinical infection during a small outbreak of whooping cough: implications for clinical diagnosis.

The transmission of whooping cough in a general practice community was followed after the identification of the first case for nearly three years. Intensive case-finding was undertaken to detect contacts of known cases of whooping cough and to take pernasal swabs from those with any cough; 102 swabs were taken. In three months 39 cases of whooping cough were clinically diagnosed, 17 (44%) of which were confirmed bacteriologically. All had a prolonged paroxysmal cough, one-third reported a catarrhal phase, 18 (46%) vomited with paroxysms and nine (23%) whooped. No isolations of Bordetella pertussis were obtained from the 84 contacts with non-paroxysmal coughs. There was no evidence that subclinical bordetella infection (showing none of the signs of whooping cough) is a common occurrence.It is probable that many recognizable cases of whooping cough are missed because it can be a milder illness than is often realized and commonly exhibits neither whooping, vomiting nor a catarrhal phase. Paroxysms may be infrequent. The diagnosis of whooping cough should be suspected from a prolonged paroxysmal cough alone.

Adolescent

Whooping cough.

Explore the source record for details and available documents.

Adult

Effect of oral therapy for treatment and prophylaxis of anaemia of pregnancy in an urban Zambian population.

The effect of iron and folic acid tablets supplied antenatally was studied in 77 urban Zambian patients with haemoglobin levels of 70% (10.2 grams) or over at first visit. No significant difference was found between treated and untreated groups. A haemoglobin level of 80% (10.2 grams) or over at first visit was found to be no guide to the likelihood of anaemia at term. The practice of providing treatment for these patients on the basis of the haemoglobin level at first visit is of doubtful value.

Administration, Oral