Ripple effects are positive or negative outcomes that are caused by efforts to implement Evidence Based Interventions (EBI) and are unplanned, unanticipated, and/or more relevant to stakeholders other than researchers and implementers.
Any EBI implementation effort includes one or more implementation strategies that are generally intended to increase the use, availability, or quality of services. Implementation scientists call these “adoption”, “reach”, and “fidelity”. For instance, providing training to providers on an EBI will increase the likelihood the provider will use the EBI, and the quality of the EBI.
But implementation strategies may have positive or negative unintended consequences, which we call ripple effects. For instance, one strategy for increasing EBI availability is state mandates for public providers. While this may increase the availability of EBIs, it may also result in increased health equity (as it results in increased access to EBIs for low-income individuals), or in “counterfeit” services as therapists adopt low-quality versions of the EBI to meet state mandates.
Ripple effects include a broad range of unexpected secondary outcomes, mediators, or process impacts resulting from implementation strategies. Ripple effects exist within an array of different types of unexpected or secondary impacts that have been described in multiple fields of study, often with differing terminology. For instance, the Medical Research Council’s guidance on conducting process evaluations of complex interventions identified “unexpected mechanisms” as an area worthy of investigation. Secondary outcomes also are central to Complexity Science and Diffusion of Innovations theory, which use the term “unintended consequences”, as well as Quality Improvement and Quality Assurance (QI/QA), which uses the term “balancing measures”, as they are essential for understanding the full balance of costs and benefits of a quality improvement effort. In implementation and treatment research some publications have referred to “spillover effects,” generally defined as benefits to intervention non-participants. Ripple effects differ from these in that they are specifically unintentional, caused by implementation strategies, can be positive, negative, or neutral, and impact any role or hierarchical level of implementation.
Research attention to ripple effects has been generally limited. Two systematic reviews conducted 25 years apart found fewer than 0.2% of studies on innovations in a broad range of fields examined whether the innovation resulted in any unplanned outcomes; other reviews have found similar absence in perioperative care improvement interventions, improvement methodologies in surgery, and interventions to reduce patient falls and infections. Unintended and unexpected ripple effects are infrequently measured even when using strategies specifically designed to consider the full range of implementation outcomes.
Our open access paper that outlines ripple effects can be found here.