Actigraphy correctly predicts sleep behavior in infants who are younger than six months, when compared with polysomnography.

Actigraphy has been widely used in adults and children. In infants, validation of actigraphy has typically used a comparison with behaviorally determined sleep state classification rather than polysomnography (PSG). This study validated actigraphy against PSG for determining sleep and waking states in infants who were younger than 6 mo. Twenty-two healthy infants, 13 term and 9 preterm, were studied at three different matched postconceptional ages. Actigraph data were compared with PSG recordings in 1-min epochs. Agreement rate (AR), predictive value for sleep, predictive value for wake, sensitivity. and specificity were calculated and compared between activity thresholds and across ages with two-way ANOVA for repeated measures. Thirty-two validation studies were analyzed. Overall AR with PSG of 93.7 +/- 1.3 and 91.6 +/- 1.8 were obtained at 2-4 wk and 5-6 mo, respectively, at the low activity threshold setting, whereas the auto activity threshold gave the best agreement with PSG at 2-4 mo (AR 89.3 +/- 1.3%). Sensitivity values of 96.2 +/- 1.1% at 2-4 wk, 91.2 +/- 1.5% at 2-4 mo, and 94.0 +/- 1.9% were obtained at these same settings. There was no difference across ages in AR or sensitivity. PVW and specificity values were low in this study. We conclude that actigraphy is a valid method for monitoring sleep in infants who are younger than 6 mo.

Increasing the evidence base for selection for undergraduate medicine: four case studies investigating process and interim outcomes.

INTRODUCTION: Prior to 1997, the University of Adelaide, Australia selected medical students according to matriculation marks alone. After extensive consultation with relevant stakeholders and examination of empirical evidence, the selection process is now based on a national written examination of reasoning and interaction skills, a structured oral assessment and a threshold matriculation score. This paper presents a series of 4 case studies examining the process related to the procedure and early interim outcomes, with the aim of adding to the evidence base for methods of medical student selection. METHODS: Data were collected from a range of sources between 1996 and 2001, including the University's central administration system, the Faculty of Health Sciences, and purpose-designed oral assessment forms and self-report student questionnaires. RESULTS: The oral assessment process has shown itself to be characterised by a high level of interassessor reliability. Equity of access has been addressed and the number of schools represented in the student intake has increased from between 10 and 15 in the final years of the old selection process to over 30 statewide under the new process. There has been a corresponding increase in the proportion of students from rural backgrounds (from an original 4-12% to 20-22%). DISCUSSION: These investigations add to the evidence base for medical school selection in that they demonstrate that an oral assessment process can be reliable and lead to early positive results in relation to student outcomes and access.

Interaction between bed sharing and other sleep environments during the first six months of life.

This investigation was carried out to determine the relationship between bed sharing and other places of infant sleep in the first six months of life, and to identify patterns of change in the place of infant sleep for infants who do and do not routinely bed share in the first six months of life. The sleep--wake behaviour and place of infant sleep were recorded, at weekly intervals, for bed sharing (n=25) and non-bed sharing (n=68) infants between 2 and 24 weeks after birth. Bed sharing infants spent a significantly increased proportion of their total sleep time per 24 h in other sleep environments which favoured close parental proximity and significantly less time in solitary sleep. Non-bed sharing infants spent a substantial proportion of their time sleeping alone from 2 weeks of age whereas the transition to sleeping alone occurred after 16 weeks for bed sharing infants. We have found that bed sharing acts as a proxy for increased close parental proximity during the first six months of life. This may be of significance in studies which examine the relationship between bed sharing and sudden infant death syndrome.