Converting measures of mental health and wellbeing into WELLBYs

This page is under construction and will be updated soon.

At the Happier Lives Institute, we evaluate the effect of interventions using subjective wellbeing (SWB) as our primary outcome. This is classically measured with questions asking people to self-report how happy or satisfied they are on a scale of 0 to 10. However, there is often too little classical SWB data available about the interventions we evaluate. Therefore, we also include in our reports the much more prevalent measures of affective mental health (MHa) such as mental distress, stress, depression, and anxiety. Is this appropriate? We have discussed this briefly before in different reports (e.g., McGuire et al., 2023). In this report we give a fuller standalone explanation of our methods. We explore whether standardised effects from MHa are an acceptable proxy for standardised effects from SWB. This is an ongoing topic of interest which we expect to update over time.

MHa measures ask about low moods, which overlaps with the wellbeing concept of ‘happiness’ (a balance of positive over negative experience).  While these concepts are theoretically distinct, our focus here is on testing the difference empirically by seeing whether the effect of an intervention is substantially different when measured on a SWB or a MHa measure. We use four different data sources, for four different interventions (psychotherapy in low- and middle-income countries, psychotherapy in high income countries, psychological interventions, and cash transfers). Although the four sources provide different results, overall, when averaged, the evidence suggests that the effects of these particular interventions on SWB are slightly larger than the effects on MHa. Hence, including MHa most likely plays a conservative role rather than overestimating role when estimating the impact of an intervention on SWB, at least in these cases. Further work could explore how far this generalises, but this indicates substituting one for another is not clearly a problem.

Just because the results are very similar between the two broad types of measures does not mean that the results are identical. Nevertheless, we think these findings suggest it is reasonable to treat MHa and SWB as being broadly equivalent considering the dearth of SWB data for evaluating interventions. We are tentatively excited about this result, as it has the potential to unlock data for ourselves and other researchers to do more and more extensive analyses where only non-ideal data are available. Of course, the long-term solution would be for those who conduct interventions to provide more SWB data.