Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT02339909 |
| Other study ID # |
REC 14/LO/1779 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
March 2015 |
| Est. completion date |
July 2016 |
Study information
| Verified date |
October 2023 |
| Source |
Imperial College London |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
This trial is a randomised controlled trial to assess whether annual attendance rates at
diabetic eye screening appointments in Kensington, Chelsea and Westminster could be improved
by offering invitees a small financial incentive. The research questions are:
1. Are incentives an effective strategy to encourage participation in the screening
programme?
2. Does the design of the financial incentive scheme affect its effectiveness in
influencing participation in health screening?
3. Does the choice of incentive scheme, if successful, attract patients who have a
different demographic or socioeconomic status to those who attend screening regularly?
4. Is offering these incentives a cost-effective strategy for enhancing participation?
Description:
An increasing emphasis is being placed on preventative healthcare in the NHS (National Health
Service). Screening programmes currently exist in many clinical areas including diabetic
retinopathy as well as breast cancer, cervical cancer and cardiovascular disease. In many
contexts the benefits of health screening are well documented, but concerns exist about the
effectiveness and cost-effectiveness of such programmes as uptake to screening may be very
poor in some, generally hard to reach, communities. There are many ways of trying to
encourage participation in health promoting activities and it is likely real shifts in
behaviour will only come about with a mix of strategies. In this study we set out to see if
we can improve screening rates in London, which has both high and low levels of deprivation
and specific populations with poor attendance. The ultimate success of a high-quality
screening program depends on the uptake rate of the population and novel solutions are
required to meet the challenge of achieving this.
Diabetes is an increasing public health concern worldwide. There are 2.9 million people
diagnosed with diabetes in the UK (United Kingdom) and an estimated 850,000 people who have
the condition but are not recognised. Whilst the rates of other vascular risk factors such as
hypertension, smoking and hypercholesterolaemia are falling, the rates of diabetes in the UK
are rising. This is despite the co-ordinated efforts of primary and secondary care prevention
programmes.
All patients with diabetes are at risk of developing diabetic retinopathy. This condition is
caused by the microscopic damage to small blood vessels to the eye. There is proliferation
(growth) of these vessels and these new fragile vessels may bleed and destroy the retina
leading to sight loss. It is estimated that in England every year 4,200 people are at risk of
blindness caused by diabetic retinopathy and there are 1,280 new cases of blindness caused by
diabetic retinopathy. It is the leading cause of sight loss in the UK in the working
population and therefore there is a significant social and financial burden associated with
the condition. However with timely diagnosis and treatment the risk of blindness can be
dramatically reduced. As this condition may well remain silent until catastrophic late
manifestations of the disease are evident, the need for an effective screening programme is
obvious.
The National Screening programme was implemented in England between 2003 and 2006. This
involves an annual retinal digital photographic screening offered to all people aged 12 years
and older diagnosed with type 1 and type 2 diabetes. The test involves administration of eye
drops to the eye and a photograph of the retina taken without contact with the eye. The
success of this screening programme is without contest. In 2011-2012, 2,587,000 people in
England aged 12 and over were identified with diabetes and over 90% were offered screening
for diabetic retinopathy. 1,911,000 received screening which equates to an uptake of 81%.
However there is significant variability in uptake in differing areas.
Although screening is offered in multiple locations including GP (general practice) surgeries
and hospitals, the poor uptake of screening in socially deprived areas is well documented.
For example, in Gloucestershire, with each increasing quintile of deprivation, diabetes
prevalence increases (odds ratio 0.84), the probability of having been screened for diabetic
retinopathy decreases (odds ratio 1.11), and the prevalence of sight-threatening diabetic
retinopathy among screened patients increases also (odds ratio of 0.98).
Since the effectiveness of any screening programme is intimately linked to the uptake by the
population (and in particular uptake by those most at risk), simple, inexpensive and cost
effective strategies are required by the NHS to influence population health behaviours in
domains where choices are often in sharp contrast to underlying intentions. This has
relevance to diabetic retinopathy screening but also more widely as we increasingly try to
prevent disease rather than simply treat it.
Incentives are central to economics and are used across the public and private sectors to
influence behaviour. Psychological phenomena from behavioural economics allow us to design
incentive-based interventions that are more effective at delivering improved outcomes.
Personal incentives have been used to motivate patients and general populations to change
their behaviour. Examples of behaviours targeted include smoking and drug use cessation.
Incentives can include cash, vouchers or benefits-in-kind and they can have a profound effect
on individual behaviour at a relatively small cost. Interest in offering incentives to foster
healthier lifestyles has increased, as the full economic and social costs of bad choices and
unhealthy behaviour have become apparent. Incentives have previously been used to improve
cancer screening rates, but they have been targeted at the providers of the service rather
than people invited to attend for screening. Financial incentives have been seen to be more
effective in increasing performance of infrequent behaviours (e.g. vaccinations) rather than
in more sustained behaviours (e.g. smoking). As screening usually requires discrete one-off
behaviours, incentives may be particularly effective in increasing their uptake.
A wider use of incentives in public health interventions is a more recent phenomenon and has
attracted controversy and concerns about whether they are effective (and cost effective) or
not. This study will provide evidence to policy makers about the role of different incentive
schemes in encouraging health promoting behaviours. We do not suggest that providing
incentives is the only answer to encouraging screening participation, but if we demonstrate
good evidence that they are effective (and cost effective), their targeted application may be
indicated. Equally demonstration that incentives of this type are not effective may prevent
unnecessary financial loss from the NHS if wider rollout of such programmes is considered.
