Annex 14. Typology of scenarios with variable inequality and overall average trends

Blakely and colleagues developed a “compass” typology visualization to describe scenarios characterized by variable (decreasing, increasing or stable) trends in three variables: overall mortality rate, absolute inequality and relative inequality (1). The approach facilitates a structured assessment of the trends and a compelling visual presentation of the data. A compass analogy is used to describe the most desirable trend (decreasing mortality alongside reduced absolute and relative inequality – “southwest”) and the least desirable trend (increasing mortality alongside increased absolute and relative inequality – “northeast”).

An adapted version of the typology is included here (Figure A14.1). For mortality rate, an adverse indicator where smaller values indicate improvements, declining overall average and declining rates in all subgroups may be accompanied by increased relative inequality. Mathematically, it is also possible to observe declining overall average alongside unchanged or declining relative inequality. As indicated in the figure, it is not mathematically possible to see unchanged overall mortality alongside incongruous absolute and relative inequality trends.

This approach has been applied to report changes in the prevalence and absolute and relative income-related inequalities in mental health (2). Other approaches to describe and interpret trends of absolute and relative inequalities have been described elsewhere (3).

FIGURE A14.1. Compass typology of overall average and inequality trends in mortality

Source: derived from Blakely et al. (1).

References

1. Blakely T, Disney G, Atkinson J, Teng A, Mackenbach JP. A typology for charting socioeconomic mortality gradients: “go southwest”. Epidemiology. 2017;28(4):594–603. doi:10.1097/EDE.0000000000000671.

2. Asada Y, Grignon M, Hurley J, Stewart SA, Smith NK, Kirkland S, et al. Trajectories of the socioeconomic gradient of mental health: results from the CLSA COVID-19 Questionnaire Study. Health Policy. 2023;131:104758. doi:10.1016/j.healthpol.2023.104758.

3. Trends in income-related health inequalities in Canada: technical report. Ottawa: Canadian Institute for Health Information; 2016 (https://secure.cihi.ca/free_products/trends_in_income_related_inequalities_in_canada_2015_en.pdf, accessed 23 September 2024).