The cost of inflammatory bowel disease in high-income settings: a Lancet Gastroenterology & Hepatology Commission.

The cost of caring for patients with inflammatory bowel disease (IBD) continues to increase worldwide. The cause is not only a steady increase in the prevalence of Crohn's disease and ulcerative colitis in both developed and newly industrialised countries, but also the chronic nature of the diseases, the need for long-term, often expensive treatments, the use of more intensive disease monitoring strategies, and the effect of the diseases on economic productivity. This Commission draws together a wide range of expertise to discuss the current costs of IBD care, the drivers of increasing costs, and how to deliver affordable care for IBD in the future. The key conclusions are that (1) increases in health-care costs must be evaluated against improved disease management and reductions in indirect costs, and (2) that overarching systems for data interoperability, registries, and big data approaches must be established for continuous assessment of effectiveness, costs, and the cost-effectiveness of care. International collaborations should be sought out to evaluate novel models of care (eg, value-based health care, including integrated health care, and participatory health-care models), as well as to improve the education and training of clinicians, patients, and policy makers.

Ineligibility and refusal to participate in randomised trials of treatments for drug dependence.

ISSUES: The aim of this study is to examine the extent to which drug-dependent patients are ineligible for or unwilling to participate in randomised clinical trials. This is important because unrepresentative sample selection is a potentially important problem for randomised trials in the drug dependence field and little is known about the magnitude of the problem. APPROACH: A total of 98 clinical trials were drawn for analysis from a systematic review of the drug dependence treatment literature. KEY FINDINGS: The trials reviewed excluded an average of 29% of potential subjects as ineligible; a further 29% of the eligible subjects were unwilling to participate. Trials comparing widely different treatments had a higher proportion of ineligible and unwilling subjects than did studies comparing more similar treatments. Experiments with large samples enrolled a smaller proportion of patients from their sampling pool than did experiments with small samples. IMPLICATIONS: Drug-dependent trial subjects are a minority of all drug patients seen in real-world clinical practice. It is necessary to improve the reporting of these potential problems in randomised trials. Systematic reviews of the literature ought to use this information to distinguish reliable from less reliable findings. CONCLUSION: Unrepresentative sample selection is a serious problem for randomised trials in the drug dependence field.

The spread of drug use: epidemic models or social interaction?

This chapter argues that models trying to explain the spread of drug use should not be based on standard epidemiological models developed to describe the spread of infectious diseases. The main weaknesses of the standard model are the lack of attention to micro-foundations and the inappropriateness of several of its assumptions in the context of drug use. An approach based on mechanisms and social interaction is argued to provide a promising alternative to the standard approach. To illustrate this, a model of the spread of drugs based on two mechanisms has been developed (observational learning and social stigma). Lastly, some of the difficulties in testing and deriving policy implications in these models are discussed.