Asthma and the motorways--one District's experience.

BACKGROUND: Proposals to widen the section of the M25 motorway that passes through East Surrey caused considerable concern and claims that the traffic on the road was responsible for an increasing prevalence of asthma. This study was designed to ascertain the prevalence of asthma-related symptoms among schoolchildren in the District and determine whether there was an association with proximity to a motorway. METHODS: A total of 2387 children aged between 13 and 14 from 17 schools in East Surrey were invited to participate in a survey of the prevalence of asthma-related respiratory symptoms. The survey instrument used was the core asthma questionnaire of the International Survey on Asthma and Allergies in Childhood (ISAAC). The children were grouped according to electoral ward of residence and comparisons were made between urban and rural wards, and the presence or absence of a section of motorway. RESULTS: The prevalence of reported symptoms varied from 2.2 per cent reporting sleep disturbance on more than one night each week to 40 per cent reporting a wheezing episode at some time in their lives; 16 per cent reported a diagnosis of asthma. The overall prevalence of symptoms did not differ greatly from that reported in other similar studies. There was a decrease in the prevalence of asthma-related symptoms in areas close to motorways, which was statistically significant for two questions. This is unlikely to be due to the rural location of the motorways. CONCLUSION: This study suggests that the motorways in East Surrey, in their present configuration, are not responsible for an increased prevalence of respiratory symptoms associated with asthma.

Changes in auditory-vocal reaction times within and across experimental sessions: preliminary observations.

Changes in auditory-vocal reaction times (AVRTs) within and across experimental sessions were studied in 13 healthy university students, all females. Subjects were required to listen to a series of synthesized vowels and utter each of the vowels as soon as they heard it. The vowels were /i/, /u/, /a/, /o/, and /ae/, each presented 14 times and all presented in random order and at irregular intervals (2.5-4.5 sec). The stimuli and the instructions were prerecorded and presented to the subjects binaurally at a comfortable intensity level via headphones in an IAC booth. Each subject performed the experimental task twice, a week apart. The stimuli and the vocal responses were tape recorded and later digitized and computer analyzed. Serial analysis of successive AVRTs revealed significant intra- and intersession decreases in AVRTs in the majority of the subjects. Increases in AVRTs were also seen, but much less frequently. The implications of these findings are discussed.

Diagnostic reasoning of high- and low-domain-knowledge clinicians: a reanalysis.

Thinking-aloud protocols provided by Joseph and Patel were reanalyzed to determine the extent to which their conclusions could be replicated by independently developed coding schemes. The data set consisted of protocols from four cardiologists (low domain knowledge = LDK) and four endocrinologists (high domain knowledge = HDK), individually working on a diagnostic problem in endocrinology. The two analyses agree that the HDK physicians related data to potential diagnoses more than did the LDK group and were more focused on the correct diagnostic components. However, the reanalysis found no meaningful difference between the groups in diagnostic accuracy, speed of diagnosis, or the breadth of the search space used to seek a solution. In the reanalysis, the HDK physicians employed more single-cue inference and less multiple-cue inference. The generalizability of results of protocol-analysis studies can be assessed by using several complementary coding schemes.