Increasing response to a postal survey of sedentary patients – a randomised controlled trial [ISRCTN45665423]

BACKGROUND: A systematic review identified a range of methods, which can influence response rates. However, analysis specific to a healthcare setting, and in particular, involving people expected to be poor responders, was missing, We examined the effect of pre-warning letters on response rates to a postal survey of sedentary patients whom we expected a low rate of response. METHODS: Participants were randomised to receive a pre-warning letter or no pre-warning letter, seven days before sending the main questionnaire. The main questionnaire included a covering letter and pre-paid return envelope. After seven days, non-responders were sent a reminder letter and seven days later, another reminder letter with a further copy of the questionnaire and return envelope. RESULTS: 627 adults, with a mean age of 48 years (SD 13, range 18 to 78) of whom 69.2% (434/627) were women, were randomised. 49.0% (307/627) of patients were allocated to receive a pre-warning letter and 51.0% (320/627) no pre-warning letter, seven days in advance of posting the main questionnaire. The final response rate to the main questionnaire was 30.0% (92/307) amongst those sent a pre-warning letter and 20.9% (67/320) not sent a pre-warning letter, with an adjusted odds ratio of 1.60 (95% CI 1.1, 2.30). CONCLUSIONS: The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated. Investigators should consider incorporating this simple intervention when conducting postal surveys, to reduce the potential for nonresponse bias and to increase the study power. Methods other than postal surveys may be needed however when a low response rate to postal surveys is likely

Developing immunity to flight security risk: prospective benefits from considering aviation security as a socio-technical eco-system

Since 9/11, preventing similar terrorist disasters has been the predominant goal of aviation security. Yet, in this paper we seek to explore why it is that despite our increased knowledge of disaster causation - aviation security systems still remain vulnerable to future exploitation by adaptive terrorists and other threat groups. We adopt a novel approach, and present early directions of how we apply the benefits of high level appreciations of socio-technical and biological eco-systems to existing complex aviation transportation security systems. We propose that by approaching aviation security as a complex socio-technical eco-system, it offers an opportunity to think beyond conventional methodologies to improve system performance in a way that, hitherto, would not have been possible. The paper concerns itself with the ability for aviation socio-technical eco-systems to hold the capacity to proactively identify and mitigate pathogenic errors and violations. This narrow view is juxtaposed with identifying methods of reducing error creation ‘before’ they become system vulnerabilities. To address this problem, the paper concludes that a fresh approach, both conceptually and operationally, is required to understand that ‘true’ foresight of latent vulnerabilities can only be achieved by a system which is ‘intelligent’ and ‘self-aware’, in other words to identify and modify hostile pathogens before they are exploited. The development of true foresight in aviation security systems is critical to the prevention of future terrorist attacks