Using Relative and Absolute Measures for Socioeconomic Inequalities in Health: Experiences from a Retrospective Cohort Study on COVID-19
Abstract
Background: One approach to reducing the burden of diseases can be to identify socioeconomically vulnerable groups. We aimed to estimate the socioeconomic inequality of in-hospital deaths using relative and absolute indices of socioeconomic inequality.
Methods: In this retrospective cohort study on Covid-19 patients; age, gender, marital status, education level, date of admission, diagnostic method, and final condition were measured. Socioeconomic inequality in in-hospital death was assessed using three approaches. We used the relative index of inequality (RII) to measure relative inequality. We used two approaches to evaluate absolute inequality: the slope index of inequality (SII) and the concentration index (ci).
Results: Overall, 587 patients’ data were collected and 42 (7.2%) of these patients died in the hospital. There were statistically significant differences between the case-fatality rates of different levels of education (P<0.001). In addition, all the inequality indices showed that the distribution of COVID-19-related deaths was higher among the lower education levels. Accordingly, after controlling the effect of age, gender, and comorbidities the RII indicated that the case fatality rate in the lowest education level was 9.42 (95% CI: 2.23 to 39.01, P<0.001) times compared to the case fatality rate in the highest level of education.
Conclusion: The results of all three approaches indicate considerable education inequality in CFR in favor of groups of high education levels. These results can improve the prioritization and impact of public health interventions, including prevention and diagnosis of Covid-19 in favor of vulnerable groups.
1. Yang L, Liu S, Liu J, et al (2020). COVID-19: immunopathogenesis and Immunotherapeutics. Signal Transduction and Targeted Therapy, 5(1): 128.
2. Velavan TP, Meyer CG (2020). The COVID‐19 epidemic. Trop Med Int Health, 25(3): 278-280.
3. World Health Organization (2023). WHO Coronavirus (COVID-19) Dashboard. Available from: https://covid19.who.int/
4. Khadka S, Hashmi FK, Usman M (2020). Preventing COVID-19 in low-and middle-income countries. Drugs Ther Perspect, 36(6): 250-252.
5. Torri E, Sbrogiò LG, Di Rosa E, et al (2020). Italian public health response to the COVID-19 pandemic: Case report from the field, insights and challenges for the department of prevention. Int J Environ Res Public Health, 17(10): 3666.
6. Baigi V, Nedjat S, Yunesian M, et al (2020). Clinical and Epidemiological Features of Hospitalized Patients with COVID-19 in Hospitals of Tehran University of Medical Sciences. Front Emerg Med, 5(2):e20.
7. Du RH, Liang LR, Yang CQ, et al (2020). Predictors of mortality for patients with COVID-19 pneumonia caused by SARS-CoV-2: a prospective cohort study. Eur Respir J, 55(5): 2000524.
8. Ruan Q, Yang K, Wang W, et al (2020). Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China. Intensive Care Med, 46(5): 846-8.
9. Liu W, Yang C, Liao Y-G et al (2022). Risk factors for COVID-19 progression and mortality in hospitalized patients without pre-existing comorbidities. J Infect Public Health, 15(1): 13-20.
10. Howe LD, Galobardes B, Matijasevich A, et al (2012). Measuring socio-economic position for epidemiological studies in low-and middle-income countries: a methods of measurement in epidemiology paper. Int J Epidemiol, 41(3): 871-886.
11. Regidor E, De Mateo S, Calle M, et al (2002). Educational level and mortality from infectious diseases. J Epidemiol Community Health, 56(9): 682-683.
12. Williamson EJ, Walker AJ, Bhaskaran K, et al (2020). Factors associated with COVID-19-related death using OpenSAFELY. Nature, 584(7821): 430-436.
13. Parolin Z, Lee EK (2022). The role of poverty and racial discrimination in exacerbating the health consequences of COVID-19. Lancet Reg Health Am, 7:100178.
14. Jung J, Manley J, Shrestha V (2020). Coronavirus infections and deaths by poverty status: time trends and patterns. Covid Economics, 31: 1-58.
15. Decoster A, Minten T, Spinnewijn J (2020). The income gradient in mortality during the Covid-19 crisis: evidence from Belgium. The Journal of Economic Inequality, 19(3): 551-570.
16. Concepción-Zavaleta MJ, Coronado-Arroyo JC, Zavaleta-Gutiérrez FE, et al (2020). Does level of education influence mortality of SARS-CoV-2 in a developing country? Int J Epidemiol, 49(6): 2091-2093.
17. Niedzwiedz CL, O’Donnell CA, Jani BD, et al (2020). Ethnic and socioeconomic differences in SARS-CoV-2 infection: prospective cohort study using UK Biobank. BMC Med, 18: 1-14.
18. Crankson S, Pokhrel S, Anokye NK (2022). Determinants of COVID-19-related length of hospital stays and long COVID in Ghana: a cross-sectional analysis. Int J Environ Res Public Health, 19(1): 527-537.
19. Mulyanto J, Kringos DS, Kunst AE (2019). Socioeconomic inequalities in healthcare utilisation in Indonesia: a comprehensive survey-based overview. BMJ Open, 9(7): e026164.
20. Vahedi S, Yazdi-Feyzabadi V, Amini-Rarani M, et al (2020). Tracking socio-economic inequalities in healthcare utilization in Iran: a repeated cross-sectional analysis. BMC Public Health, 20(1): 1-12.
21. Huisman M, Kunst AE, Mackenbach JP (2003). Socioeconomic inequalities in morbidity among the elderly; a European overview. Soc Sci Med, 57(5): 861-73.
22. Burström B, Tao W (2020). Social determinants of health and inequalities in COVID-19. Eur J Public Health, 30(4): 617-618.
23. Chen JT, Krieger N (2021). Revealing the unequal burden of COVID-19 by income, race/ethnicity, and household crowding: US county versus zip code analyses. J Public Health Manag Pract, 27(1): S43-S56.
24. Takian A, Raoofi A, Kazempour-Ardebili S (2020). COVID-19 battle during the toughest sanctions against Iran. Lancet, 395(10229): 1035.
25. Moreno-Betancur M, Latouche A, Menvielle G, et al (2015). Relative index of inequality and slope index of inequality: a structured regression framework for estimation. Epidemiology, 26(4): 518-527.
26. Sergeant JC, Firth D (2006). Relative index of inequality: definition, estimation, and inference. Biostatistics, 7(2):213-224.
27. Baigi V, Nedjat S, Hosseinpoor AR, et al (2018). Socioeconomic inequality in health domains in Tehran: A population-based cross-sectional study. BMJ Open, 8(2): e018298.
28. Wagstaff A (2011). The concentration index of a binary outcome revisited. Health Econ, 20(10): 1155-1160.
29. Koolman X, Van Doorslaer E (2004). On the interpretation of a concentration index of inequality. Health Econ, 13(7): 649-656.
30. Martins-Filho PR, de Souza Araújo AA, Quintans-Júnior LJ, et al (2020). COVID-19 fatality rates related to social inequality in Northeast Brazil: a neighbourhood-level analysis. J Travel Med, 27(7): 128.
31. Almasi-Hashiani A, Abbasi M, Tavakol M, et al (2019). Decomposing socioeconomic inequality in health literacy in Iran: A concentration index approach.
Int J Prev Med, 10: 184.
32. Danaei G, Harirchi I, Sajadi HS, et al (2019). The harsh effects of sanctions on Iranian health. The Lancet, 394(10197): 468-469.
33. Murphy A, Abdi Z, Harirchi I, et al (2020). Economic sanctions and Iran's capacity to respond to COVID-19. Lancet Public Health, 5(5): e254.
34. Salamati P, Chaufan C (2019). The harsh effects of sanctions on Iranian health. The Lancet, 394(10213): 1990-1.
35. Gallo Marin B, Aghagoli G, Lavine K, et al (2021). Predictors of COVID‐19 severity: A literature review. Rev Med Virol, 31(1): 1-10.
36. Jin J-M, Bai P, He W, et al (2020). Gender differences in patients with COVID-19: focus on severity and mortality. Front Public Health, 8:152.
37. Bayliss EA, Ellis JL, Steiner JF (2005). Subjective assessments of comorbidity correlate with quality of life health outcomes: initial validation of a comorbidity assessment instrument. Health Qual Life Outcomes, 3(1): 1-8.
38. DeSalvo KB, Fan VS, McDonell MB, et al (2005). Predicting mortality and healthcare utilization with a single question. Health Serv Res, 40(4): 1234-46.
39. Najafi F, Pasdar Y, Shakiba E, et al (2019). Validity of Self-reported Hypertension and Factors Related to Discordance Between Self-reported and Objectively Measured Hypertension: Evidence From a Cohort Study in Iran. J Prev Med Public Health, 52(2): 131-139.
40. Prinja S, Jeet G, Kumar R (2012). Validity of self-reported morbidity. Indian J Med Res, 136(5): 722-724.
2. Velavan TP, Meyer CG (2020). The COVID‐19 epidemic. Trop Med Int Health, 25(3): 278-280.
3. World Health Organization (2023). WHO Coronavirus (COVID-19) Dashboard. Available from: https://covid19.who.int/
4. Khadka S, Hashmi FK, Usman M (2020). Preventing COVID-19 in low-and middle-income countries. Drugs Ther Perspect, 36(6): 250-252.
5. Torri E, Sbrogiò LG, Di Rosa E, et al (2020). Italian public health response to the COVID-19 pandemic: Case report from the field, insights and challenges for the department of prevention. Int J Environ Res Public Health, 17(10): 3666.
6. Baigi V, Nedjat S, Yunesian M, et al (2020). Clinical and Epidemiological Features of Hospitalized Patients with COVID-19 in Hospitals of Tehran University of Medical Sciences. Front Emerg Med, 5(2):e20.
7. Du RH, Liang LR, Yang CQ, et al (2020). Predictors of mortality for patients with COVID-19 pneumonia caused by SARS-CoV-2: a prospective cohort study. Eur Respir J, 55(5): 2000524.
8. Ruan Q, Yang K, Wang W, et al (2020). Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China. Intensive Care Med, 46(5): 846-8.
9. Liu W, Yang C, Liao Y-G et al (2022). Risk factors for COVID-19 progression and mortality in hospitalized patients without pre-existing comorbidities. J Infect Public Health, 15(1): 13-20.
10. Howe LD, Galobardes B, Matijasevich A, et al (2012). Measuring socio-economic position for epidemiological studies in low-and middle-income countries: a methods of measurement in epidemiology paper. Int J Epidemiol, 41(3): 871-886.
11. Regidor E, De Mateo S, Calle M, et al (2002). Educational level and mortality from infectious diseases. J Epidemiol Community Health, 56(9): 682-683.
12. Williamson EJ, Walker AJ, Bhaskaran K, et al (2020). Factors associated with COVID-19-related death using OpenSAFELY. Nature, 584(7821): 430-436.
13. Parolin Z, Lee EK (2022). The role of poverty and racial discrimination in exacerbating the health consequences of COVID-19. Lancet Reg Health Am, 7:100178.
14. Jung J, Manley J, Shrestha V (2020). Coronavirus infections and deaths by poverty status: time trends and patterns. Covid Economics, 31: 1-58.
15. Decoster A, Minten T, Spinnewijn J (2020). The income gradient in mortality during the Covid-19 crisis: evidence from Belgium. The Journal of Economic Inequality, 19(3): 551-570.
16. Concepción-Zavaleta MJ, Coronado-Arroyo JC, Zavaleta-Gutiérrez FE, et al (2020). Does level of education influence mortality of SARS-CoV-2 in a developing country? Int J Epidemiol, 49(6): 2091-2093.
17. Niedzwiedz CL, O’Donnell CA, Jani BD, et al (2020). Ethnic and socioeconomic differences in SARS-CoV-2 infection: prospective cohort study using UK Biobank. BMC Med, 18: 1-14.
18. Crankson S, Pokhrel S, Anokye NK (2022). Determinants of COVID-19-related length of hospital stays and long COVID in Ghana: a cross-sectional analysis. Int J Environ Res Public Health, 19(1): 527-537.
19. Mulyanto J, Kringos DS, Kunst AE (2019). Socioeconomic inequalities in healthcare utilisation in Indonesia: a comprehensive survey-based overview. BMJ Open, 9(7): e026164.
20. Vahedi S, Yazdi-Feyzabadi V, Amini-Rarani M, et al (2020). Tracking socio-economic inequalities in healthcare utilization in Iran: a repeated cross-sectional analysis. BMC Public Health, 20(1): 1-12.
21. Huisman M, Kunst AE, Mackenbach JP (2003). Socioeconomic inequalities in morbidity among the elderly; a European overview. Soc Sci Med, 57(5): 861-73.
22. Burström B, Tao W (2020). Social determinants of health and inequalities in COVID-19. Eur J Public Health, 30(4): 617-618.
23. Chen JT, Krieger N (2021). Revealing the unequal burden of COVID-19 by income, race/ethnicity, and household crowding: US county versus zip code analyses. J Public Health Manag Pract, 27(1): S43-S56.
24. Takian A, Raoofi A, Kazempour-Ardebili S (2020). COVID-19 battle during the toughest sanctions against Iran. Lancet, 395(10229): 1035.
25. Moreno-Betancur M, Latouche A, Menvielle G, et al (2015). Relative index of inequality and slope index of inequality: a structured regression framework for estimation. Epidemiology, 26(4): 518-527.
26. Sergeant JC, Firth D (2006). Relative index of inequality: definition, estimation, and inference. Biostatistics, 7(2):213-224.
27. Baigi V, Nedjat S, Hosseinpoor AR, et al (2018). Socioeconomic inequality in health domains in Tehran: A population-based cross-sectional study. BMJ Open, 8(2): e018298.
28. Wagstaff A (2011). The concentration index of a binary outcome revisited. Health Econ, 20(10): 1155-1160.
29. Koolman X, Van Doorslaer E (2004). On the interpretation of a concentration index of inequality. Health Econ, 13(7): 649-656.
30. Martins-Filho PR, de Souza Araújo AA, Quintans-Júnior LJ, et al (2020). COVID-19 fatality rates related to social inequality in Northeast Brazil: a neighbourhood-level analysis. J Travel Med, 27(7): 128.
31. Almasi-Hashiani A, Abbasi M, Tavakol M, et al (2019). Decomposing socioeconomic inequality in health literacy in Iran: A concentration index approach.
Int J Prev Med, 10: 184.
32. Danaei G, Harirchi I, Sajadi HS, et al (2019). The harsh effects of sanctions on Iranian health. The Lancet, 394(10197): 468-469.
33. Murphy A, Abdi Z, Harirchi I, et al (2020). Economic sanctions and Iran's capacity to respond to COVID-19. Lancet Public Health, 5(5): e254.
34. Salamati P, Chaufan C (2019). The harsh effects of sanctions on Iranian health. The Lancet, 394(10213): 1990-1.
35. Gallo Marin B, Aghagoli G, Lavine K, et al (2021). Predictors of COVID‐19 severity: A literature review. Rev Med Virol, 31(1): 1-10.
36. Jin J-M, Bai P, He W, et al (2020). Gender differences in patients with COVID-19: focus on severity and mortality. Front Public Health, 8:152.
37. Bayliss EA, Ellis JL, Steiner JF (2005). Subjective assessments of comorbidity correlate with quality of life health outcomes: initial validation of a comorbidity assessment instrument. Health Qual Life Outcomes, 3(1): 1-8.
38. DeSalvo KB, Fan VS, McDonell MB, et al (2005). Predicting mortality and healthcare utilization with a single question. Health Serv Res, 40(4): 1234-46.
39. Najafi F, Pasdar Y, Shakiba E, et al (2019). Validity of Self-reported Hypertension and Factors Related to Discordance Between Self-reported and Objectively Measured Hypertension: Evidence From a Cohort Study in Iran. J Prev Med Public Health, 52(2): 131-139.
40. Prinja S, Jeet G, Kumar R (2012). Validity of self-reported morbidity. Indian J Med Res, 136(5): 722-724.
| Files | ||
| Issue | Vol 52 No 6 (2023) | |
| Section | Original Article(s) | |
| DOI | https://doi.org/10.18502/ijph.v52i6.12993 | |
| Keywords | ||
| Socioeconomic inequality Relative index of inequality Concentration index | ||
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How to Cite
1.
Mehdizadeh P, Baigi V, Teymourzadeh E. Using Relative and Absolute Measures for Socioeconomic Inequalities in Health: Experiences from a Retrospective Cohort Study on COVID-19. Iran J Public Health. 2023;52(6):1269-1277.
