Abstract

Design - Population based case-control study.

Setting - Data from a nationwide childhood diabetes case register were linked with data from the nationwide Swedish Medical Birth Registry.

Subjects - Data from a total of 4,584 diabetic children born after 1973 and diagnosed with diabetes from 1978 to 1992 were studied. For each child with insulin dependent diabetes three control children were randomly selected from among all infants born in the same year and at the same hospital as the proband.

Main outcome measures - Birth weight, gestation, maternal age and parity, number of previous spontaneous abortions, and sex specific birth weight by gestational week expressed as multiples of the standard deviation (SD).

Results - There was a clear trend in the odds ratio for childhood onset diabetes according to SD of birth weight. The odds ratio (95% confidence interval) for small for gestational age after stratification for maternal age, parity, smoking habits, and maternal diabetes was 0.81 (0.65 to 0.99) and for large for gestational age after similar stratification was 1.20 (1.02 to 1.42).

Conclusions - Intrauterine conditions that affect prenatal growth seem also to affect the risk of development of childhood diabetes in the way previously described for postnatal growth: a poor growth decreases and an excess growth increases the risk. The mechanism for this association is unclear.

Departments of Paediatrics and Epidemiology and Public Health,
University of Umea,
S-901 85 Umea,
Sweden
Gisela Dahlquist, professor of paediatrics

Department of Internal Medicine,
Uppsala University,
Uppsala,
Sweden
Sara Sandberg Bennich, MD student

Tornblad Institute,
University of Lund,
Lund,
Sweden
Bengt Kallen, professor

Correspondence to: Professor Dahlquist.

Abstract

Design - Follow up study of mortality in relation to employment grade and car ownership over 25 years.

Setting - The first Whitehall study.

Subjects - 18,133 male civil servants aged 40-69 years who attended a screening examination between 1967 and 1970.

Main outcome measure - Death.

Results - Grade of employment was a strong predictor of mortality before retirement. For men dying at ages 40-64 the lowest employment grade had 3.12 times the mortality of the highest grade (95% confidence interval 2.4 to 4.1). After retirement the ability of grade to predict mortality declined (rate ratio 1.86; 1.6 to 2.2). A non-work based measure of socioeconomic status (car ownership) predicted mortality less well than employment grade before retirement but its ability to predict mortality declined less after retirement. Using a relative index of inequality that was sensitive to the distribution among socioeconomic groups showed employment grade and car ownership to have independent associations with mortality that were of equal magnitude after retirement. The absolute difference in death rates between the lowest and highest employment grades increased with age from 12.9 per 1000 person years at ages 40-64 to 38.3 per 1000 at ages 70-89.

Conclusions - Socioeconomic differences in mortality persist beyond retirement age and in magnitude increase with age. Social differentials in mortality based on an occupational status measure seem to decrease to a greater degree after retirement than those based on a non-work measure. This suggests that alongside other socioeconomic factors work itself may play an important part in generating social inequalities in health in men of working age.

Department of Epidemiology and Public Health,
University College London Medical School,
London WC1E 6BT
M G Marmot, professor
Martin J Shipley, senior lecturer in medical statistics

Correspondence to: Professor Marmot.

Abstract

Design - A double blind randomised trial with xylitol administered in chewing gum.

Setting - Eleven day care nurseries in the city of Oulu. Most of the children had had problems with recurrent acute otitis media.

Subjects - 306 day care children: 149 children in the sucrose group (76 boys; mean (SD) age 4.9 (1.5) years) and 157 in the xylitol group (80 boys; 5.0 (1.4) years).

Intervention - Either xylitol (8.4g a day) or sucrose (control) chewing gum for two months.

Main outcome measures - The occurrence of acute otitis media and antimicrobial treatment received during the intervention and nasopharyngeal carriage of S pneumoniae.

Results - During the two month monitoring period at least one event of acute otitis media was experienced by 31/149 (20.8%) children who received sucrose compared with 19/157 (12.1%) of those receiving chewing gum containing xylitol (difference 8.7%; 95% confidence interval 0.4% to 17.0%; P = 0.04). Significantly fewer antimicrobials were prescribed among those receiving xylitol: 29/157 (18.5%) children had at least one period of treatment versus 43/149 (28.9%) (difference 10.4%; 0.9% to 19.9%; P = 0.032). The carriage rate of S pneumoniae varied from 17.4% to 28.2% with no difference between the groups. Two children in the xylitol group experienced diarrhoea, but no other adverse effects were noted among the xylitol users.

Conclusion - Xylitol seems to have a preventive effect against acute otitis media.

Department of Paediatrics,
University of Oulu,
FIN-90220 Oulu,
Finland
M Uhari, associate professor
T Kontiokari, research fellow
Marjo Niemela, research fellow

Division of Microbiology,
University Hospital of Oulu,
FIN-90220 Oulu,
Finland
M Koskela, head of division

Correspondence to: Professor Uhari.

Abstract

Design - Multipractice comparative study.

Setting - 33 general practices and a central department of clinical microbiology in Aarhus County, Denmark.

Subjects - 222 women aged 18-25 years who for any reason had a gynaecological examination.

Interventions - Endocervical and urethral swabs were obtained by the women's general practitioners. The same women when at home then collected a first void urine sample, a midstream urine sample, and a vaginal flush sample (using a vaginal pipette) and mailed them to the laboratory.

Main outcome measures - C trachomatis detected by the polymerase chain reaction and the ligase chain reaction. Eight tests for C trachomatis were performed for every woman. When two of the eight yielded positive results the patient was considered infected.

Results - The overall prevalence of C trachomatis infection was 11.2% (23/205 women). Test sensitivities in samples obtained by general practitioners, samples obtained at home subjected to polymerase chain reaction, and samples obtained at home subjected to ligase chain reaction were 91%, 96%, and 100% respectively. The corresponding specificities were 100%, 92.9%, and 99.5%.

Conclusions - The diagnostic efficacy of samples obtained by women at home and mailed to the laboratory was as good as for samples obtained by a general practitioner when using the ligase chain reaction. This may have important implications for the practicability of screening for this common, often asymptomatic, and treatable infection.

Department of Infectious Diseases,
Aarhus University Hospital,
PP Orumsgade 11,
DK-8000 Aarhus C,
Denmark
Lars Ostergaard, senior registrar

Department of Clinical Microbiology,
Aarhus University Hospital,
DK-8000 Aarhus C
Jens K Moller, director

Research Unit for General Practice,
University of Aarhus,
DK-8OOO Aarhus C
Berit Andersen, research assistant
Frede Olesen, consultant physician

Correspondence to: Dr Ostergaard.

Abstract

Design - Study of general practice catchment area maps.

Setting - London borough of Lambeth.

Subjects - 60 out of the 71 general practices in Lambeth.

Main outcome measures - Practice catchment area size with corrections for numbers of doctors and patients.

Results - Catchment area size varied greatly between practices, showing an almost 150-fold difference between the largest and smallest practices. This size differential was even more marked when the size of the catchment area was corrected for the number of general practitioners in the practice, where a 300-fold difference was found. substantial differences existed between practices in each of the four locally assigned quality bands. The weakest practices had catchment areas three times as large as those of the strongest practices. When corrected for medical staffing, the difference was eight times as great. A calculated measure of patient dispersion showed that the practice population of the strongest practices was four times as densely clustered as that of the weakest practices, whose patients were more widely geographically dispersed.

Conclusions - Large variations exist in the size of catchment areas of inner city practices even when corrected for numbers of doctors and patients. These differences are associated with variations in quality of care.

Department of General Practice,
United Medical and Dental Schools of Guy's and St Thomas's Hospitals,
London SE11 6SP
Clare Jenkins, research associate
John Campbell, senior lecturer

Correspondence to: Ms Jenkins.