Abstract

Coverage with evidence development (CED) has been promoted as a means of providing early access to innovative technologies. The policy provides for funding of a treatment or technology conditional on gathering data through a clinical trial or registry designed to determine its effectiveness and to identify rare adverse events. CED has been used with varying degrees of success in the US, Switzerland, Canada and the UK, 1 but the rigour of data collected has been a particular concern.
Treatment registers have been criticized for their poor quality of data, particularly inadequate coverage and incompleteness.2,3 Inadequate coverage may lead to selection bias when patients who fit inclusion criteria for the register are missed. Incomplete data entry risks biased outcomes reporting. Both affect the reliability of the conclusions drawn. Randomized controlled trials (RCT) therefore continue to be considered the ‘gold standard’ in evidence-based medicine and are found at the summit of hierarchies of evidence, with observational studies in the foothills. 4 However, RCTs have important limitations including uncertain generalizability and failure to identify important, rare safety concerns. Bradford Hill, the architect of the RCT stated: ‘Any belief that the controlled trial is the only way would mean not that the pendulum had swung too far but that it had come right off the hook’. 5 Observational data give insight into real-world clinical practice and can be used by decision makers in health technology assessment (HTA).6–9 They could be a powerful tool for CED because they have the potential to reduce uncertainty around treatment costs, prevalence, safety, natural history and provider experience.10,11
Routine use of active surveillance would enhance the standing and usefulness of treatment register data and so increase their value in CED decision-making. Active surveillance is related to the approach taken by the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) group which has provided reporting standards that aim to foster and improve quality in the use and production of observational studies. 12 This is important work but is limited to describing problems which have occurred in the past and the ex post statistical methods to adjust for these failings (i.e. handling missing data and loss to follow-up). By contrast, active surveillance seeks to drive quality prospectively, rather than in retrospect.
The active surveillance approach involves proactive monitoring of the quality and coverage of data submitted to a register, and regular communication with those submitting data, with a view to improving their quality. There are five important aspects of active surveillance:
The components of active surveillance underpinned a successful national audit in the UK of the management of the open abdomen. 13 The abdomen is sometimes left ‘open’ as part of the surgical treatment of complex intra-abdominal problems that make closure difficult, such as severe sepsis. In 2009, the National Institute for Health Care Excellence (NICE) published guidance on negative wound pressure in the management of the open abdomen. It considered that the evidence on safety was inadequate, recommending that if hospitals use the procedure they should make special arrangements for clinical governance and data collection. To collect and analyse the data, a national audit of management and outcomes of open abdomen was organized.
The project posed a particular challenge in terms of coverage because the clinical need for management of an open abdomen is a relatively rare event, and patients present acutely in both specialist units and general hospitals. The audit was led by a steering group with a smaller data subgroup of academics, clinicians and representatives of NICE to oversee active surveillance.
A minimum dataset was agreed by the groups to focus efforts. As the event is rare and acute, it was decided that hospitals needed to be alerted to the presence of patients on their wards for whom data submission was necessary. To achieve this, submissions from hospitals were triangulated against those in a database maintained by the Intensive Care National Audit and Research Centre (ICNARC). When patients were identified on the ICNARC database but were not on the audit database, their clinicians were contacted and encouraged to submit data to the National Audit. To maintain quality, data validation was undertaken by academics and specialist clinicians who identified clinically questionable entries, and communicated with hospital staff to verify the information.
The study yielded the largest independent survey of management of the open abdomen ever reported and was published in 2013. 13
Use of active surveillance would improve the quality of observational data and thereby increase their value as an adjunct to clinical trial data when making decisions about the use of health-care interventions. Active surveillance involves simple practical steps that should be incorporated into the planning of any new register.
