BACKGROUND AND PURPOSE:

• Number of COVID-19 cases in Italy grew exponentially
  • Beginning of February: 3 cases | Related to international travel
  • February 20: Severe case in Lombardy not tied to travel
  • Within 14 days, multiple cases, many critical
• SARS-CoV-2 likely circulating in Italy undetected since January
• Onder et al. (JAMA, 2020) provide a review on the Italian experience with the COVID-19 pandemic

METHODS:

• Review (through March 17)
• Setting: Italy
• Surveillance of COVID-19 cases
  • The Italian National Institute of Health (ISS) : Data From all 19 regions and 2 autonomous provinces
  • COVID-19 identification: real-time RT-PCR
  • Fatality rate was calculated as the number of deaths/number of cases

RESULTS:

• Overall COVID-19 fatality rate: 7.2%
  • Total fatalities: 1625
  • Total cases: 22,512
• The fatality rate in Italy is higher than other countries
  • Italy’s case fatality rate: 7.2%
  • China’s case fatality rate: 2.3%

Possible Factors Contributing to Italy’s High Fatality Rate

Age of Population

• 23% of the Italian population is ≥65 years
• Stratified by age: The case-fatality rate in Italy and China are
  • Similar for age groups age groups 0 to 69 years
  • Higher in Italy for those in age groups ≥70 years
• Cases skewed toward people >70 years in Italy
  • Italy: 37.6%
  • China: 11.9%
• Age >90 years
  • Italy: 687 cases with 22.7% fatality
  • China: No cases reported

Case Definition of COVID-19 Death

• Presently, no standardized definition for COVID-19 fatality
• Italy: Fatality defined as anyone who died with a positive test for SARS-CoV-2
  • May overestimate death rate
• Researchers conducted a chart review of Italian subsample (335 patients) identified as a COVID-19 fatality
  • Mean age: 79.5 years | 30.0% women
  • Pre-existing conditions
    • Ischemic heart disease: 30% (117 patients)
    • Diabetes: 35.5% (126 patients)
    • Active cancer: 20.3% (72 patients)
    • Atrial fibrillation: 24.5% (87 patients)
    • Dementia: 6.8% (24 patients)
    • History of stroke: 9.6% (34 patients)
  • Number of conditions
    • No disease history: 0.8% (3 patients)
    • Single disease: 25.1% (89 patients)
    • 2 diseases: 25.6% (91 patients)
    • 3 or more diseases: 48.5% (172 patients)
• Comorbidities themselves may independently drive mortality risk

Different Testing Approaches

• Initial testing strategy: Symptomatic individuals and their contacts
  • Abandoned due to increasing spread and healthcare system burden
• Subsequent prioritization strategy: Severe cases that need hospitalization
  • Prioritization strategy drives increase in positive test rate (19.3%)
  • Fatality rate will be calculated based on a denominator with more severe cases
    • Case fatality rate with initial strategy (February): 3.1%
    • Case fatality with prioritization strategy (March) 7.2%
• South Korea uses a very broad testing strategy and therefore denominator will include les severe COVID-19 cases
  • Italy’s case fatality rate: 7.2%
  • South Korea’s case fatality rate: 1.0%

CONCLUSION:

• Italy’s high case-fatality rate could be explained by
  • Older population
  • Any fatality with a positive SARS-CoV-2 result is reported as a COVID-19 fatality; however, cause of death may be related to underlying co-morbidity
  • Current testing strategies prioritize sicker patients which will alter the fatality rate
• The authors stress that to get a more complete picture of case fatalities in different countries there needs to be
  • Clear reporting on age, sex, comorbidities, and testing strategies
  • Clear definitions of COVID-19 fatalities

Learn More – Primary Sources:

Case-Fatality Rate and Characteristics of Patients Dying in Relation to COVID-19 in Italy

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