‘Dark logic’: theorising the harmful consequences of public health interventions

Abstract

Although it might be assumed that most public health programmes involving social or behavioural rather than clinical interventions are unlikely to be iatrogenic, it is well established that they can sometimes cause serious harms. However, the assessment of adverse effects remains a neglected topic in evaluations of public health interventions. In this paper, we first argue for the importance of evaluations of public health interventions not only aiming to examine potential harms but also the mechanisms that might underlie these harms so that they might be avoided in the future. Second, we examine empirically whether protocols for the evaluation of public health interventions do examine harmful outcomes and underlying mechanisms and, if so, how. Third, we suggest a new process by which evaluators might develop ‘dark logic models’ to guide the evaluation of potential harms and underlying mechanisms, which includes: theorisation of agency-structure interactions; building comparative understanding across similar interventions via reciprocal and refutational translation; and consultation with local actors to identify how mechanisms might be derailed, leading to harmful consequences. We refer to the evaluation of a youth work intervention which unexpectedly appeared to increase the rate of teenage pregnancy it was aiming to reduce, and apply our proposed process retrospectively to see how this might have strengthened the evaluation. We conclude that the theorisation of dark logic models is critical to prevent replication of harms. It is not intended to replace but rather to inform empirical evaluation.

Research Review: Harnessing the power of individual participant data in a meta‐analysis of the benefits and harms of the Incredible Years parenting program

“…A systematic review planned to examine burden on families participating in a parenting program, but found no studies reporting these outcomes. Harmful effects of psychosocial interventions can be adverse effects on expected outcomes, or adverse effects on unexpected outcomes (Bonell et al, 2015).…”

“…The data therefore allow to study some aspects of harm (i.e., adverse effects on outcomes related to the program aims), but not other aspects (i.e., adverse effects on outcomes other than those related to the program aims) (Bonell et al, 2015). Table 1 provides an overview of the fourteen included trials.…”

“…The outcomes included in the primary trials were most likely included based on the hypothesis that they might reveal benefits, rather than harms. Revealing harmful effects sometimes requires different outcome measures (Bonell et al, 2015;Scott & Young, 2016). Thus, our study was equipped to pick up on some aspects of harm (i.e., adverse effects on outcomes related to the program aims), but not other aspects (i.e., adverse effects on outcomes other than those related to the program aims).…”

“…Similarly, potential harmful effects are almost never studied in parenting program research, while it is well-established that social interventions can sometimes cause harm (e.g., Bonell, Jamal, Melendez-Torres, & Cummins, 2015). Better understanding of a program's benefits and harms requires full disclosure by researchers of all included measures, and large enough numbers of participants to be able to detect small effects and estimate them precisely.…”

In memoriam: the contributions to public health research of Farah Jamal, BA, MSc, PhD

“…A recent paper published in this journal, and awarded the European Society for Prevention Research President's Award for Outstanding Prevention Science Research Paper in 2015, argued that evaluators of public health interventions should give more consideration to prehypothesising their potentially iatrogenic effects 6. By doing so, harms might more readily be detected and underlying mechanisms be better understood, so that they might be avoided in future interventions.…”