This paper estimates a standardised mortality ratio (SMR) for death due to COVID-19 among people in prisons in England and Wales between 1 March 2020 and 26 February 2021. Over this period, prisons in England and Wales reported 121 deaths related to COVID-19. The SMR is 3.33 (95% C.I. 2.77–3.98), meaning there were 3.33 times more deaths among people in prisons than expected given the age and sex of the population

Braithwaite, I

Edge, C

Lewer, D

English

UCL Discovery

Page 1 Indirect age- and sex-standardisation of COVID-19-related mortality rates for the prison population of England and Wales   8 March 2021 Isobel Braithwaite [1], Chantal Edge [2], Dan Lewer [2] Affiliations 1. UCL Public Health Data Science Research Group, Institute of Health Informatics, University College London, London, UK  2. UCL Collaborative Centre for Inclusion Health, London, UK  Summary This paper estimates a standardised mortality ratio (SMR) for death due to COVID-19 among people in prisons in England and Wales between 1 March 2020 and 26 February 2021. Over this period, prisons in England and Wales reported 121 deaths related to COVID-19. The SMR is 3.33 (95% C.I. 2.77–3.98), meaning there were 3.33 times more deaths among people in prisons than expected given the age and sex of the population. Introduction This paper accompanies a Spotlight article in Lancet Respiratory Medicine outlining the case for early vaccination of people in prisons and prison staff (REFERENCE). The UK, like many countries, has had higher rates of COVID-19 infection amongst people in prisons than the general population throughout the pandemic. There were over 10,000 confirmed positive COVID-19 cases amongst people in prisons up to end January 2021.1 Relative numbers of cases should be treated with caution due to potentially different case ascertainment.  We therefore used indirect standardisation2 to compare the COVID-19 mortality rate among people in prisons with that in the general population, accounting for the age and sex structure of people in prisons. Page 2 Data sources General population estimates. We used the most recent ONS general populations (June 2019) for England and Wales, published on NomisWeb.3 COVID-19 deaths in the general population. We used Office for National Statistics data for occurrences of deaths (i.e. the actual date of death) involving COVID-19 (deaths where COVID-19 is mentioned on the death certificate).4 Prison population size. We used the prison population (all types of custody) published in Offender Management Statistics Quarterly.5 COVID-19 deaths in people in prisons. We used the Her Majesty’s Prison and Probation Service (HMPPS) COVID-19 Summary tables (data to 31 January 2021, with data for February collated from weekly HMPPS reports)1. We used the number COVID-19-related deaths, defined as deaths within 28 days of a positive test or where COVID-19 was confirmed post-mortem, and/or where it was assessed as a contributory factor. Although COVID-19 was not necessarily the main cause of death in all of these cases, the general population ONS data similarly includes individuals where COVID-19 was mentioned on the death certificate but was not necessarily the main cause of death. Data analysis We estimated the proportion of the general population who died each month in each age- and sex-group, then applied these proportions to the prison population to estimate the number of expected deaths each month. The oldest age group in prison population data is ‘70+’. We therefore did the following sensitivity analyses of the expected (general population) mortality rate in this group: • Base scenario: mortality rate for 70-79 year-olds in the general population • Low scenario: mortality rates for 70-74 year-olds in the general population. • High scenario: mortality rates for all 70+ year-olds in the general population. These rates affect the denominator in the SMR so a low ‘expected’ mortality rate translates to a higher SMR.  We estimated the number of ‘expected’ deaths (‘E’) among people in prisons, had they experienced the same mortality rates as people of the same age and sex in the general population of England and Wales. Page 3 We then compared this with the observed number of deaths among people in prisons (‘O’), determined their ratio (Standardised Mortality Ratio = O/E), and calculated exact Poisson 95% confidence intervals using R version 4.0.3.  Results  There were 121 deaths amongst people in prisons related to COVID-19 from March 2020 to February 2021. Given the age and sex structure of this population, we expected 36.3 deaths over this period; this gave an SMR of 3.33 (95% C.I. 2.77–3.98). The sensitivity analyses showed that these findings are sensitive to different assumptions about the distribution in age of the 2% of people in prisons population who are aged 70 and over. The SMRs were 2.42 (95% C.I. 2.01–2.90) when we applied reference mortality rates for the whole general population aged 70+, and 3.71 (95% C.I. 3.08-4.43) when we applied reference mortality rates for 70-74 year-olds. Page 4 Table 1: Number of deaths related to COVID-19 in the general population of England and Wales  2020          2021   Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Male             15-24 5 12 3 0 1 0 0 2 3 1 9 9 25-29 7 19 6 1 0 0 1 3 3 6 14 7 30-39 34 70 17 8 0 3 3 10 28 15 98 42 40-49 86 267 68 23 16 5 10 31 93 67 294 132 50-59 291 921 244 99 26 19 24 106 331 228 911 478 60-69 635 1,922 525 195 47 33 57 301 886 591 1,987 1,045 70-74 585 1,714 548 194 49 30 67 304 900 565 1,767 824 70-79 1,342 4,096 1,321 491 118 82 149 742 2,124 1,376 4,075 1,840 70+ 3,606 12,901 4,603 1,694 399 229 427 2,012 6,420 4,495 12,677 5,381 Female             15-24 7 4 2 1 0 0 0 0 4 2 6 2 25-29 6 11 1 0 0 0 0 1 5 2 11 6 30-39 19 55 13 6 2 3 3 7 18 11 58 30 40-49 68 142 50 23 3 6 5 17 69 45 180 106 50-59 164 465 123 45 13 10 14 60 191 174 584 255 60-69 303 968 304 116 33 27 36 146 443 355 1,232 592 70-74 280 918 321 142 48 15 34 155 495 362 1,181 487 70-79 680 2,379 857 351 101 36 82 402 1,270 879 2,811 1,205 70+ 2,307 11,035 4,972 1,750 383 205 314 1,592 5,324 3,972 12,613 5,339 Table 2: Deaths related to COVID-19 per million in the general population of England and Wales  Population estimate  2020          2021   Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Male              15-24 3,576,081 1 3 1 0 0 0 0 1 1 0 3 3 25-29 2,039,665 3 9 3 0 0 0 0 1 1 3 7 3 30-39 3,937,345 9 18 4 2 0 1 1 3 7 4 25 11 40-49 3,720,131 23 72 18 6 4 1 3 8 25 18 79 35 50-59 3,949,699 74 233 62 25 7 5 6 27 84 58 231 121 60-69 3,062,502 207 628 171 64 15 11 19 98 289 193 649 341 70-74 1,416,786 413 1,210 387 137 35 21 47 215 635 399 1,247 582 70-79 2,376,998 565 1,723 556 207 50 34 63 312 894 579 1,714 774 70+ 3,600,327 1,002 3,583 1,278 471 111 64 119 559 1,783 1,248 3,521 1,495 Female             15-24 3,576,081 2 1 1 0 0 0 0 0 1 1 2 1 25-29 2,039,665 3 5 0 0 0 0 0 0 2 1 5 3 30-39 3,937,345 5 14 3 2 1 1 1 2 5 3 15 8 40-49 3,720,131 18 38 13 6 1 2 1 5 19 12 48 28 50-59 3,949,699 42 118 31 11 3 3 4 15 48 44 148 65 60-69 3,062,502 99 316 99 38 11 9 12 48 145 116 402 193 70-74 1,416,786 198 648 227 100 34 11 24 109 349 256 834 344 70-79 2,376,998 286 1,001 361 148 42 15 34 169 534 370 1,183 507 70+ 3,600,327 641 3,065 1,381 486 106 57 87 442 1,479 1,103 3,503 1,483    Page 5  Table 3: Number of people in prisons in England and Wales  2020          2021   Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Male             15-24 13,343   12,343   12,243   12,052   25-29 13,817   13,858   13,287   13,045   30-39 24,725   24,764   24,146   24,193   40-49 14,001   14,178   13,704   13,797   50-59 8,222   8,179   7,944   7,890   60-69 3,252   3,279   3,161   3,181   70+ 1,780   1,766   1,674   1,669   Female             15-24 396   356   333   317   25-29 549   517   476   452   30-39 1,346   1,354   1,161   1,192   40-49 871   856   793   784   50-59 415   409   367   347   60-69 100   107   102   101   70+ 26   24   23   24   Table 4: Expected number of deaths (x1000) related to COVID-19 among people in prisons in England and Wales, based on mortality rates in the general population  2020          2021   Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Male             15-24 19 45 11 0 3 0 0 7 10 3 30 30 25-29 47 129 41 7 0 0 7 20 20 38 90 45 30-39 214 440 107 50 0 19 18 61 172 92 602 258 40-49 324 1,005 256 88 61 19 37 114 343 248 1,090 490 50-59 606 1,917 508 205 54 39 48 213 666 455 1,820 955 60-69 674 2,041 557 209 50 35 59 311 914 614 2,064 1,085 70-74 735 2,153 688 242 61 37 79 359 1,063 666 2,082 971 70-79 1,005 3,067 989 365 88 61 105 523 1,496 966 2,861 1,292 70+ 1,783 6,378 2,276 831 196 112 199 935 2,985 2,084 5,877 2,494 Female             15-24 1 0 0 0 0 0 0 0 0 0 1 0 25-29 2 3 0 0 0 0 0 0 1 0 2 1 30-39 6 19 4 2 1 1 1 2 5 3 18 9 40-49 16 33 12 5 1 1 1 4 15 9 38 22 50-59 17 49 13 5 1 1 1 6 18 15 51 22 60-69 10 32 10 4 1 1 1 5 15 12 41 20 70-74 5 17 6 2 1 0 1 3 8 6 20 8 70-79 7 26 9 4 1 0 1 4 12 9 28 12 70+ 17 80 36 12 3 1 2 10 34 26 84 36    Page 6  Table 5: Summary of observed and expected deaths related to COVID-19 among people in prisons in England and Wales   Observed deaths Expected deaths (base) Expected deaths (low) Expected deaths (high) 2020 Mar 4 2.9 2.7 3.7  Apr 17 8.8 7.9 12.2  May 4 2.5 2.2 3.8  Jun 2 0.9 0.8 1.4  Jul 0 0.3 0.2 0.4  Aug 0 0.2 0.2 0.2  Sep 0 0.3 0.3 0.4  Oct 5 1.3 1.1 1.7  Nov 15 3.7 3.2 5.2  Dec 24 2.5 2.2 3.6 2021 Jan 15 8.7 7.9 11.8  Feb 35 4.2 3.9 5.5  Total 121 36.3 32.6 49.9  SMR (95% C.I.)  3.33 (2.77-3.98) 3.71 (3.08-4.43) 2.42 (2.01-2.90) Figure 1: Observed and expected deaths related to COVID-19 among people in prisons in England and Wales    Mar-20Apr-20May-20Jun-20Jul-20Aug-20Sep-20Oct-20Nov-20Dec-20Jan-21Feb-21010203040Number of deaths related to COVID-19Number of deaths amongpeople in prisonsin England & WalesExpected deaths based on ageand sex-specific rates in thegeneral populationPage 7 References 1 Her Majesty’s Prison and Probation Service. HMPPS COVID-19 statistics: January 2021. 2021. https://www.gov.uk/government/statistics/hmpps-covid-19-statistics-january-2021 (accessed March 3, 2021). 2 Curtin L, Klein R. Direct standardization (age-adjusted death rates). 1995. https://www.cdc.gov/nchs/data/statnt/statnt06rv.pdf (accessed Feb 20, 2021). 3 Nomis - official labour market statistics. Population estimates - local authority based by single year of age. 2021. https://www.nomisweb.co.uk/ (accessed March 3, 2020). 4 Office for National Statistics. Deaths registered weekly in England and Wales by age and sex: covid-19. 2021. https://www.ons.gov.uk/datasets/weekly-deaths-age-sex/editions/covid-19/versions/20 (accessed March 8, 2021). 5 HM Prison Service. Offender management statistics quarterly: January to March 2020. 2020. https://www.gov.uk/government/statistics/offender-management-statistics-quarterly-january-to-march-2020--2 (accessed March 3, 2020).  

Indirect age- and sex-standardisation of COVID-19-related mortality rates for the prison population of England and Wales

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Indirect age- and sex-standardisation of COVID-19-related mortality rates for the prison population of England and Wales

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