We anticipate many benefits from a patient safety market. Organisations are given a clear policy signal to reduce PAE rates, are told by how much but are free to use whatever mechanisms best suit their local needs. The reward for excellent organisations that beat targets is that spare credits can be sold, yielding a financial reward that can be reinvested in improving care.
However, are we allowing unsafe organisations to buy their way out of trouble? In reality, an organisation that buys credits is not rewarded for poor performance but pays a transparent financial penalty. It would be difficult to sustain an organisation that has to spend money to prop up poor practice. The incentive to change is direct and unavoidable, and accountability hard to evade when PAEs are measured in the bottom line.
There is also significant opportunity for new players to enter the market. Businesses may emerge to exploit ways of minimising PAEs. A manufacturer of computer prescribing systems could audit their impact on medication errors, and the number of safety credits generated if a system were installed. Remotely monitoring the health status of older people at home could demonstrate a reduction in falls due to early intervention generating safety credits. Entrepreneurs could pay consumers to wear medication allergy armbands by demonstrating the bands reduce PAEs due to inappropriate medication. Brokers could help organisations find credits, agree a price, arrange their purchase and meet regulatory requirements. Aggregators could help smaller organisations with similar safety profiles to work together, sharing experiences, minimising resource utilisation on harm reduction projects and maximising their ability to generate credits.
To develop and test this new approach, we must understand the impact of the different possible market settings and ensure that benefits of error reduction strategies outweigh costs. We need to recognise that there is not a single market design but that a broad spectrum of design and implementation options are available, ranging from lighter weight models through to large, expensive and potentially heavily bureaucratic implementations. The evidence for the most effective market settings and designs will come from a number of sources. First, we need to learn from existing MBC approaches such as carbon trading. Careful consideration needs to be given to current experience with baseline-setting mechanisms, the regulator’s role, auditing and verification procedures so that consensus can be reached on these issues by the healthcare community, as well as on the structure of the marketplace itself (will it be a registry, a clearing house or a trading floor?). The market should ensure that large organisations do not distort credit prices. Some strategies will require early retirement of capital stock and generate short-term losses, or acquiring expensive new systems like electronic health records, while benefits are longer term.
Exploring the costs and benefits of different points in this large space of policy and implementation options is unlikely to be feasible through large-scale trials alone. In silico computer simulations offer a powerful alternate experimental model, which can help test out these many different market variations quickly and cheaply.19
Once there is sufficient evidence from simulations and other analyses that a particular MBC model shows promise in principle, the next step will undoubtedly require one or more small pilot studies. Pilot studies would be followed by larger-scale trials, for example using cluster randomisation, at a regional level among hospitals, to ensure that we are making evidence-based policy about harm reduction.