Why are highly effective preventive behavioural interventions adopted slowly, if at all? Dr Katherine Pryor and Dr Kevin Volpp write in the New England Journal of Medicine that firstly, historically, far more resources have been devoted to treating disease than to preventing it.
In 2002, Knowler et al reported results of a landmark study – a large, randomised, controlled trial comparing a behavioural intervention with medical therapy in the prevention of diabetes.1 Over a mean follow-up period of 2.8 years, the lifestyle-modification programme, known as the Diabetes Prevention Programme (DPP), reduced the incidence of diabetes by 58% as compared with placebo among people with elevated fasting and post-load plasma glucose concentrations. Metformin reduced the incidence of diabetes by 31% as compared with placebo.
Despite these findings, Dr Katherine Pryor and Dr Kevin Volpp at the Centre for Health Incentives and Behavioural Economics and the department of medical ethics and health policy, Perelman School of Medicine, University of Pennsylvania, Philadelphia write in the New England Journal of Medicine that insurers have been slow to provide coverage for DPP-like interventions. In 2016, the Centres for Medicare and Medicaid Services piloted the programme and determined that it improved the quality of patient care and reduced net Medicare spending, prompting a goal of expanding the DPP nationwide by 2018.
Although coverage of metformin has been ubiquitous since it was introduced in the US in 1995, many private insurers started covering the DPP only recently.
Financial incentives for tobacco cessation during pregnancy provide another example of an effective behavioural intervention that hasn’t been translated into practice. Smoking during pregnancy is a leading cause of maternal and neonatal morbidity and mortality, particularly among socially disadvantaged women and their children, and has long been a public health target.
In the US, such smoking rates have decreased only marginally in recent decades. A Cochrane review concluded that financial incentives are the most effective intervention in this population and can lead to quit rates up to four times higher than those achieved with other interventions. But such incentives haven’t been implemented in routine care of pregnant women.
Pryor and Volpp ask why are highly effective preventive interventions adopted slowly, if at all?
They write that the first issue is that, historically, far more resources have been devoted to treating disease than to preventing it; in 2015, only 3% of health care dollars were spent on preventive services. However, ongoing shifts in health financing are creating incentives for providers to pay more attention to modifiable risks such as antenatal smoking. Hospitals participating in accountable care organisations, for example, save thousands of dollars for each neonatal intensive care unit stay they prevent.
Second, treatments determined by the US Food and Drug Administration (FDA) to be safe and effective are usually covered by insurers regardless of their cost, but preventive services have been held to a higher standard: they are often assessed on the basis of whether they generate a positive return on investment and save money in the short term. This disparity leads to over-provision of treatments and under-provision of preventive services, a trend that is exacerbated by high turnover in many health insurance markets. Because insurance contracts tend to be only 1 year long, insurers don’t want to spend money to prevent disease in members who may be covered by a different insurer in the near future.
They write: "Even Medicare – which typically covers beneficiaries for life – holds preventive services to a higher standard, applying cost-effectiveness analyses when making coverage decisions about preventive services but not treatments. This double standard has resulted in coverage of cost-ineffective therapies with prices of up to hundreds of thousands of dollars per quality-adjusted life-year, including treatments of questionable benefit (such as Avastin [bevacizumab] for metastatic breast cancer after the FDA withdrew support for this use).2 A recent study showed that reallocating current Medicare expenditures toward “dominant” (cost-saving and health-increasing) interventions would result in efficiency gains and improvement in the aggregate health of Medicare beneficiaries at no additional cost.3
"Third, behavioural interventions often represent unfamiliar territory for providers. Writing a prescription is generally easy and routine, and medications are heavily marketed and seen as being easier to broadly disseminate with predictable efficacy. But this assumption doesn’t always hold true. The diabetes-prevention trial, for example, found a less heterogeneous effect in the behavioural-intervention group than the metformin group: the DPP was associated with a substantial reduction in the incidence of diabetes regardless of patients’ baseline risk, but only the highest-risk patients in the metformin group saw a similar benefit.4
"Fourth, many providers seem largely unaware of the high rates of medication nonadherence among their patients and don’t have effective tools for improving adherence. Prescribing a medication is simple for a provider but taking a medication does not appear to be simple for many patients. Outside of clinical trials, adherence to medications is often low. In the year after a heart attack, for example, only 40 to 45% of patients take their medications as prescribed.
"Finally, concerns about scalability are often a barrier in the deployment of proven behavioural interventions."
The authors write: "Consider financial incentives for antenatal smoking cessation: such a programme would require an intensive schedule of in-person visits for biochemical assessment of abstinence. Although such assessments could be built into the standard prenatal care schedule in which urine collection during office visits is common, the program would still require a shift in what providers do during visits. Assessing smoking status and counselling against ongoing tobacco use are already part of the routines of antenatal care providers but overseeing a reward system tied to smoking cessation would be new.
"There is no readily available infrastructure for clinics to manage such a programme and developing one might require a third party. Health plans could be the third party that assesses cotinine test results and administers rewards, but this would need to be done in a way that minimises delays and administrative complexity."
Pryor and Volpp write that these barriers signal a need to rethink and optimise the infrastructure and platforms on which health services are currently delivered. For example, leveraging Web-based technologies or wireless devices would address many scalability concerns and help facilitate adoption of certain behavioural interventions.
They say: “Consider the DPP-like behavioural intervention: it is labour- and time-intensive for both staff and participants, with requirements including supervised physical-activity sessions, individualised coaching, and case managers. There are geographic limitations in availability, and only a small fraction of people with prediabetes enrol. However, online versions of DPP-like interventions now exist and feature greater schedule flexibility, a personal coach, and online peer-support groups, eliminating the need for in-person assessments.”
Pryor and Volpp say that online programmes result in weight loss similar to that seen in the standard DPP.5 Web-based platforms have been used successfully in contingency management for both chronic disease and substance abuse. In these programs, biochemical markers such as carbon monoxide and blood glucose or vital signs such as blood pressure can be assessed by means of virtual observation of patients using monitoring equipment in their homes. Such platforms facilitate important innovations in supporting management of a growing range of diseases and care for hard-to-reach populations.
The authors write: “For health care’s transformation from a volume- to a value-based framework to be successful, we think that putting coverage of preventive services and treatments on more even footing will deliver great value. Historically, preventive services have been adopted only if they have been proven to save money, whereas treatments have been evaluated on the basis of their benefits and risks, without consideration of costs. The slow movement toward coverage and implementation of behavioural interventions may accelerate substantially as population-based financing becomes the norm.
“Payment reform has the potential to bring about a paradigm shift whereby all services are evaluated using the same standard: Do they improve health at a reasonable price? Such a shift could increase insurers’ willingness to cover high-value preventive services and providers’ interest in designing ways to facilitate the uptake and deployment of those services on a broader scale – enabling us to achieve better health at lower cost.”
[link url="https://www.nejm.org/doi/full/10.1056/NEJMp1716272"]New England Journal of Medicine article[/link]