Prospective study of factors predicting uptake of smoking in adolescents.

Risk factors for the uptake of cigarette smoking were examined prospectively in 2159 non-smoking secondary schoolchildren aged 11-13 who participated in a survey in 1983 and were followed up 30 months later, by which time 35 per cent had taken up smoking. In a multivariate logistic model, the strongest predictors to emerge were prior experimentation with cigarettes and sex, with more girls (41%) than boys (30%) starting to smoke. Other predictors of taking up smoking were being uncertain about smoking in the future, reporting having been drunk, having a boy or girl friend, believing teachers and friends would not mind if they took up smoking, and giving lower estimates of prevalence of smoking among teachers. Parental smoking behaviour and attitudes, beliefs about the effects of smoking on health, opinions about smoking and perceived strictness of parents did not predict take up of smoking when other variables were controlled for. The odds of taking up smoking varied from 0.24 (risk = 0.19) for a child with the most favourable combination of risk factors to 3.49 (risk = 0.78) for a child with the worst prognosis. These results differ from those of many cross sectional studies and hence indicate the importance of a prospective approach to this type of research.     

Antibody response to bacteriophage hyaluronidase in acute glomerulonephritis after group A streptococcal infection

In a test of the hypothesis that lysogeny of group A streptococci by a temperate bacteriophage might confer nephritogenicity, 283 sera from 69 patients were examined for IgG and IgM antibodies to M 49 streptococcal bacteriophage hyaluronidase. The IgG and IgM response to bacteriophage hyaluronidase was greatest in M 49 streptococci-infected individuals with nephritis, but M 49 streptococci-infected subjects without nephritis also had a greater immune response than did subjects infected with serotypes other than M 49. Although antibody to bacterial hyaluronidase was detected in all Streptococcus-infected groups, antibody to M 49 streptococcal bacteriophage hyaluronidase usually was found in only M 49 streptococci-infected patients. Although the greatest IgG and IgM antibody response to bacteriophage hyaluronidase can be demonstrated in individuals with glomerulonephritis, the antibody response does not indicate a direct relation of lysogeny and nephritis because subjects with and without nephritis after M 49 streptococcal infection all had a significant rise in antibody titer.     

Developmental changes in chickens' masked thresholds

Masked thresholds were estimated at four frequencies (.25, .5, 1, and 2 kHz) in three levels of broadband noise (approximately 0, 10, and 20 dB/Hz) in over 100 chickens at 0 and 4 days of age. An adaptive procedure was based on delays in ongoing peeps that occurred when chicks heard the tones over the background noise. Masked thresholds decreased an average of 1 dB per day immediately after birth. This increasing sensitivity is more likely due to nonsensory factors, similar to distraction masking reported in human neonates, than to improving frequency resolution. Masked thresholds in these neonates are otherwise affected by spectrum level and frequency in the same way as the responses of mature subjects: thresholds increase by nearly 1 dB for each dB of increase in the spectrum level of the masker, and by approximately 3 dB for each octave of frequency. Thus, although elevated by some nonsensory effect, masked thresholds in newborn chicks are similar to those in humans. © 1993 John Wiley & Sons Inc.     

The use and cost of HIV service provision in England in 1996. National Prospective Monitoring System (NPMS) Steering Group and NPMS Working Party on Costs.

OBJECTIVE: The aim of the study was to measure the use and estimate the cost of HIV service provision in England. DESIGN AND SETTING: Standardised activity and case-severity data were collected prospectively in 10 English HIV clinics (5 London and 5 non-London sites) for the periods 1 January 1996 to 30 June 1996 and 1 July 1996 to 31 December 1996 and linked to unit cost data. In total, 5440 patients with HIV infection attended during the first 6 months and 5708 during the second 6 months in 1996. MAIN OUTCOME MEASURES AND RESULTS: The mean number of inpatient days per patient-year for patients with AIDS was 19.7 [95% confidence interval (CI): 13.7 to 25.7] for January to June and 20.8 (95% CI: 15.3 to 26.4) for July to December 1996. The mean number of outpatient visits for asymptomatic patients with HIV infection was 14.8 (95% CI: 11.9 to 17.6) and 13.3 (95% CI: 10.8 to 15.7) for the respective periods and 16.1 (95% CI: 13.21 to 18.97) and 15.7 (95% CI: 11.2 to 20.2), respectively, for patients with symptomatic non-AIDS (i.e. symptomatic patients with HIV infection but without AIDS-defining conditions). Substantial centre-to-centre variation was observed, suggesting that many clinics can continue the shift from an inpatient- to an outpatient-based service. Cost estimates per patient-year for HIV service provision for 1996 varied from 4695 Pounds (95% CI: 3769 Pounds to 5648 Pounds) for asymptomatic patients, to 7605 Pounds (95% CI: 6273 Pounds to 8909 Pounds) for symptomatic non-AIDS patients to 20,358 Pounds (95% CI: 17,681 Pounds to 23,206 Pounds) for patients with AIDS. CONCLUSIONS: Different combinations of antiretroviral therapy affect the cost estimates of HIV service provision differently. Anticipated reduction in inpatient-related activity through the increased use of combination antiretroviral therapy will further shift service provision from an inpatient- to outpatient-based service and reduce costs per patient-year. The extent and duration of such effects are currently unknown. The long term effects of combination treatment on the morbidity and mortality patterns of individuals infected with HIV are also currently unknown, as are their implications on the use and cost of HIV service provision. Multicentre databases like the National Prospective Monitoring System (NPMS) will provide healthcare professionals with information to improve existing services and anticipate the impact of new developments.     

Closed versus open kinematic chain measurements of subtalar joint eversion: implications for clinical practice

Subtalar joint (STJ) range of motion is most critical during the support phase of the gait cycle. The purpose of this study was to determine what differences exist between measures of maximal STJ eversion in open chain and closed chain positions. STJ eversion as a component of STJ pronation was measured in nonweightbearing (NWB) and full weightbearing (WB) positions on 17 subjects who had no significant biomechanical or orthopaedic abnormality. STJ WB eversion was significantly greater than NWB passive ROM. These results indicate that accurate assessment of STJ eversion as a component of pronation requires measurement in a functional WB position as well as in a NWB position. Rehabilitation of persons with lower quarter injuries or disabilities require assessment of ROM in WB positions so that a more accurate and complete evaluation can be done allowing the clinician to make an appropriate diagnosis and treatment.J Orthop Sports Phys Ther 1988;9(9):310-314.