RESUMEN
The size and concentration of exhaled particles may influence respiratory infection transmission risk. We assessed variation in exhaled particle production between individuals, factors associated with high production and stability over time. We measured exhaled particle production during tidal breathing in a sample of 79 healthy volunteers, using optical particle counter technology. Repeat measurements (several months after baseline) were obtained for 37 of the 79 participants. Multilevel linear regression models of log transformed particle production measures were used to assess risk factors for high production. Stability between measurements over time was assessed using Lin's correlation coefficients. Ninety-nine percent of expired particles were <1µm in diameter. Considerable variation in exhaled particle production was observed between individuals and within individuals over time. Distribution of particle production was right skewed. Approximately 90% of individuals produce <150 particles per litre in normal breathing. A few individuals had measurements of over 1000 particles per litre (maximum 1456). Particle production increased with age (p<0.001) and was associated with high tree pollen counts. Particle production levels did not remain stable over time [rho 0.14 (95%CI -0.10, 0.38, p=0.238)]. Sub-micron particles conducive to airborne rather than droplet transmission form the great majority of exhaled particles in tidal breathing. There is a high level of variability between subjects but measurements are not stable over time. Production increases with age and may be influenced by airway inflammation caused by environmental irritants. Further research is needed to determine whether the observed variations in exhaled particle production affect transmission of respiratory infection.
RESUMEN
OBJECTIVES: e-Health refers to the organisation and delivery of health services and information using the internet and related technologies. We investigated the perceptions of primary care staff towards e-health initiatives in the NHS Connecting for Health programme and whether front-line staff are ready to implement such changes. DESIGN: Twenty participants from different professional groups were purposively selected for interview, based on their current computer usage. The same practice staff were subsequently observed in order to gain an insight into how they use computers. SUBJECTS: Practice staff (doctors, nurses, practice managers and receptionists) who will be expected to use new information technology and primary care trust (PCT) staff who are involved in its implementation were selected to participate in this study. SETTING: A north London PCT with 62 general practices. Four practices were selected for the study. RESULTS: Analysis of the interviews and the observational data yielded six recurrent themes that have a bearing on readiness to use information and communication systems to support clinical care: perceptions of technology and NHS Connecting for Health; issues relating to resources; patient choice; matters relating to confidentiality and security; political pressures; and how information technology is currently used within primary care. CONCLUSIONS: At the time of the study the systems that form part of NHS Connecting for Health, apart from the Quality Management and Analysis System (QMAS), were not implemented across the PCT. All the practices in the study acknowledged the benefits new technology would bring to the workplace, but there were also some common concerns, which suggest that staff working in primary care practices are not ready for e-health. Successful implementation of the NHS Connecting for Health programme rests on identifying, acknowledging and overcoming these concerns. A different approach might be required for those practices that have made very little progress in using email or moving towards an electronic patient record. This study suggests that a mistrust of technology and fears as to the heavy initial workload involved in becoming fully computerised have dissuaded some practices from embracing e-health. If NHS Connecting for Health is to be a success, implementation teams might need to focus initially on practices that have been reluctant to use technology to support both clinical care and the day-to-day work of the practice.
