title: Impact of H1N1 on socially disadvantaged populations: summary of a systematic review.
abstract: BACKGROUND
  Previous reviews found that the H1N1 pandemic was associated with a large proportion of hospitalizations, severe illness, workplace absenteeism, and high costs. However, the burden among socially disadvantaged groups of the population is unclear. This is a summary of a previously published systematic review commissioned by the World Health Organization on the burden of H1N1 pandemic (influenza A/Mexico/2009 (H1N1)) among socially disadvantaged populations.
  
  
  METHODS
  MEDLINE and EMBASE were searched to identify studies reporting hospitalization, severe illness, and mortality attributable to the 2009 H1N1 pandemic among socially disadvantaged populations, including ethnic minorities and low-income or lower-middle-income economy countries (LIC/LMIC). SAS and Review Manager were used to conduct random effects meta-analysis.
  
  
  RESULTS
  Forty-eight cohort studies and 14 companion reports including 44 777 patients were included after screening 787 citations and 164 full-text articles. Twelve of the included studies provided data on LIC/LMIC, including one study from Guatemala, two from Morocco, one from Pakistan, and eight from India, plus four companion reports. The rest provided data on ethnic minorities living in high-income economy countries (HIC). Significantly more hospitalizations were observed among ethnic minorities versus nonethnic minorities in two North American studies [1313 patients, odds ratio (OR) 2·26 (95% confidence interval: 1·53-3·32)]. Among hospitalized patients in HIC, statistically significant differences in intensive care unit admissions (n = 8 studies, 15 352 patients, OR 0·84 [0·69-1·02]) and deaths (n = 6 studies, 14 757 patients, OR 0·85 [95% CI: 0·73-1·01]) were not observed.
  
  
  CONCLUSIONS
  We found significantly more hospitalizations among ethnic minorities versus nonethnic minorities in North America, yet no differences in intensive care unit admissions or deaths among H1N1-infected hospitalized patients were observed in North America and Australia. Our results suggest a similar burden of H1N1 between ethnic minorities and nonethnic minorities living in HIC.
authors.affiliation: Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ON, Canada.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Tricco
authors.affiliation: Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ON, Canada.
authors.forename: Erin
authors.initials: E
authors.lastname: Lillie
authors.affiliation: Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ON, Canada.
authors.forename: Charlene
authors.initials: C
authors.lastname: Soobiah
authors.affiliation: Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ON, Canada.|Continuing Education and Professional Development, University of Toronto, Toronto, ON, Canada.
authors.forename: Laure
authors.initials: L
authors.lastname: Perrier
authors.affiliation: Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ON, Canada.|Division of Geriatrics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Straus
mesh_terms: D005006:Ethnicity; D014943:Global Health; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality* / Q000821:virology; D058873:Pandemics; D012959:Socioeconomic Factors; D016019:Survival Analysis
keywords: Ethnic minority; H1N1 subtype; influenza A; low-income country; low-middle-income country; vulnerable populations
references.citation: J Assoc Physicians India. 2011 Jan;59:14-6, 18
references.pmid: 21751659
references.citation: PLoS One. 2012;7(6):e39437
references.pmid: 22761796
references.citation: Euro Surveill. 2011 Jun 09;16(23):
references.pmid: 21679676
references.citation: Clin Infect Dis. 2010 Jun 1;50(11):1498-504
references.pmid: 20420514
references.citation: Vaccine. 2010 Apr 19;28(18):3180-4
references.pmid: 20189488
references.citation: N Engl J Med. 2009 Nov 12;361(20):1925-34
references.pmid: 19815860
references.citation: BMJ. 2010 Mar 18;340:c1279
references.pmid: 20299694
references.citation: Euro Surveill. 2011 Feb 10;16(6):
references.pmid: 21329643
references.citation: J Infect Dev Ctries. 2010 Dec 23;4(12):834-41
references.pmid: 21252465
references.citation: CMAJ. 2010 Feb 23;182(3):257-64
references.pmid: 20093297
references.citation: Control Clin Trials. 1986 Sep;7(3):177-88
references.pmid: 3802833
references.citation: Anaesth Intensive Care. 2011 May;39(3):384-91
references.pmid: 21675057
references.citation: Euro Surveill. 2010 Jun 17;15(24):
references.pmid: 20576236
references.citation: Commun Dis Intell Q Rep. 2010 Jun;34(2):102-9
references.pmid: 20677419
references.citation: Med J Aust. 2011 Feb 21;194(4):169-74
references.pmid: 21401456
references.citation: Indian J Pediatr. 2010 Sep;77(9):981-5
references.pmid: 20799074
references.citation: Stat Med. 2002 Jun 15;21(11):1539-58
references.pmid: 12111919
references.citation: Epidemiol Infect. 2011 Jan;139(1):27-40
references.pmid: 20920380
references.citation: J Infect. 2010 Feb;60(2):168-74
references.pmid: 20036689
references.citation: Euro Surveill. 2009 Dec 17;14(50):
references.pmid: 20070939
references.citation: Ann Acad Med Singap. 2010 Apr;39(4):283-8
references.pmid: 20473452
references.citation: Clin Infect Dis. 2011 Jan 1;52 Suppl 1:S189-97
references.pmid: 21342894
references.citation: Indian J Crit Care Med. 2010 Apr;14(2):77-82
references.pmid: 20859491
references.citation: Pediatr Infect Dis J. 2010 Jul;29(7):591-4
references.pmid: 20589976
references.citation: J Obstet Gynaecol Can. 2010 May;32(5):443-447
references.pmid: 20500952
references.citation: BJOG. 2011 Jan;118(2):232-9
references.pmid: 21040393
references.citation: Euro Surveill. 2009 Oct 22;14(42):
references.pmid: 19883543
references.citation: Int Arch Med. 2010 Oct 27;3:26
references.pmid: 20979619
references.citation: MMWR Morb Mortal Wkly Rep. 2010 Jan 8;58(51):1436-40
references.pmid: 20057350
references.citation: Pediatr Crit Care Med. 2010 Sep;11(5):603-9
references.pmid: 20308929
references.citation: Euro Surveill. 2009 Oct 22;14(42):
references.pmid: 19883546
references.citation: Ann Epidemiol. 2011 Aug;21(8):623-30
references.pmid: 21737049
references.citation: Hum Vaccin. 2011 Jan-Feb;7 Suppl:217-25
references.pmid: 21922688
references.citation: Int J Gynaecol Obstet. 2011 Apr;113(1):32-5
references.pmid: 21315351
references.citation: MMWR Morb Mortal Wkly Rep. 2009 Dec 11;58(48):1341-4
references.pmid: 20010508
references.citation: Lancet. 2010 Nov 27;376(9755):1846-52
references.pmid: 21030071
references.citation: N Engl J Med. 2009 Nov 12;361(20):1935-44
references.pmid: 19815859
references.citation: Indian J Pathol Microbiol. 2011 Apr-Jun;54(2):323-5
references.pmid: 21623082
references.citation: MMWR Morb Mortal Wkly Rep. 2009 Sep 4;58(34):941-7
references.pmid: 19730406
references.citation: Emerg Infect Dis. 2010 Jan;16(1):100-2
references.pmid: 20031050
references.citation: CMAJ. 2010 Mar 9;182(4):349-55
references.pmid: 20159893
references.citation: Crit Care Med. 2010 Oct;38(10):2059-61
references.pmid: 20625279
references.citation: J Infect Dis. 2011 Mar 15;203(6):828-37
references.pmid: 21278213
references.citation: Obstet Gynecol. 2010 Apr;115(4):717-726
references.pmid: 20308830
references.citation: Eur J Clin Microbiol Infect Dis. 2010 Nov;29(11):1327-47
references.pmid: 20623384
references.citation: Clin Microbiol Infect. 2011 Sep;17(9):1355-8
references.pmid: 21679373
references.citation: Med J Aust. 2010 May 17;192(10):617-22
references.pmid: 20477746
references.citation: Indian J Crit Care Med. 2010 Jul;14(3):113-20
references.pmid: 21253344
references.citation: J Trop Pediatr. 2011 Apr;57(2):87-90
references.pmid: 20554513
references.citation: CMAJ. 2010 Dec 14;182(18):1981-7
references.pmid: 21059773
references.citation: Emerg Infect Dis. 2009 Dec;15(12):2004-7
references.pmid: 19961687
references.citation: Clin Med (Lond). 2009 Dec;9(6):534-8
references.pmid: 20095293
references.citation: Influenza Other Respir Viruses. 2010 May 1;4(3):129-40
references.pmid: 20409209
references.citation: MMWR Morb Mortal Wkly Rep. 2009 Aug 28;58(33):913-8
references.pmid: 19713879
references.citation: Chest. 2010 Apr;137(4):752-8
references.pmid: 19933372
references.citation: Euro Surveill. 2009 Aug 27;14(34):
references.pmid: 19712648
references.citation: N Z Med J. 2010 Apr 09;123(1312):45-53
references.pmid: 20389317
references.citation: Lung India. 2011 Jan;28(1):11-6
references.pmid: 21654979
references.citation: Thorax. 2010 Jul;65(7):645-51
references.pmid: 20627925
references.citation: Influenza Other Respir Viruses. 2013 Sep;7 Suppl 2:54-58
references.pmid: 24034485
references.citation: JAMA. 2010 Apr 21;303(15):1517-25
references.pmid: 20407061
references.citation: WMJ. 2010 Aug;109(4):201-8
references.pmid: 20945721
references.citation: MMWR Morb Mortal Wkly Rep. 2009 May 22;58(19):536-41
references.pmid: 19478723
references.citation: J Coll Physicians Surg Pak. 2011 Feb;21(2):97-102
references.pmid: 21333241
references.citation: Disaster Med Public Health Prep. 2009 Dec;3 Suppl 2:S109-16
references.pmid: 19952883
references.citation: J Infect Dev Ctries. 2010 Sep 03;4(8):468-71
references.pmid: 20818097
references.citation: PLoS One. 2012;7(2):e31696
references.pmid: 22348122
references.citation: Chest. 2010 May;137(5):1195-7
references.pmid: 20139224