Medical and economic burden of influenza in the elderly population in central and eastern European countries

Abstract

Influenza affects 5-15% of the population during an epidemic. In Western Europe, vaccination of at-risk groups forms the cornerstone of influenza prevention. However, vaccination coverage of the elderly (> 65 y) is often low in Central and Eastern Europe (CEE); potentially because a paucity of country-specific data limits evidence-based policy making. Therefore the medical and economic burden of influenza were estimated in elderly populations in the Czech Republic, Hungary, Kazakhstan, Poland, Romania, and Ukraine. Data covering national influenza vaccination policies, surveillance and reporting, healthcare costs, populations, and epidemiology were obtained via literature review, open-access websites and databases, and interviews with experts. A simplified model of patient treatment flow incorporating cost, population, and incidence/prevalence data was used to calculate the influenza burden per country. In the elderly, influenza represented a large burden on the assessed healthcare systems, with yearly excess hospitalization rates of ~30/100,000. Burden varied between countries and was likely influenced by population size, surveillance system, healthcare provision, and vaccine coverage. The greatest burden was found in Poland, where direct costs were over EUR 5 million. Substantial differences in data availability and quality were identified, and to fully quantify the burden of influenza in CEE, influenza reporting systems should be standardized. This study most probably underestimates the real burden of influenza, however the public health problem is recognized worldwide, and will further increase with population aging. Extending influenza vaccination of the elderly may be a cost-effective way to reduce the burden of influenza in CEE.

Keywords: cost of illness; elderly; health care system; influenza; public health; vaccination.

Figure 1. Relative healthcare burden in elderly patients per setting per country. Relative healthcare burden in Euro per setting varies considerably by country. Self-managed: influenza-like illness (ILI) and acute respiratory infection (ARI) patients that do not contact a healthcare professional; Outpatient: ILI and ARI patients that visit a healthcare professional or are referred to a GP after hospital discharge; Inpatient: Patients treated in a hospital (intensive care unit (ICU) or non-ICU) setting.

Figure 2. Influenza‐related infections and hospitalizations in target countries, week 15, Season 2011–12. Source: EuroFlu weekly bulletin. ILI, Influenza-like illness; ARI, Acute Respiratory Infection; SARI, Severe Acute Respiratory Infection; N/A, Not Available. *SARI values are estimates from EuroFlu graphs and are the count of hospitalizations in participating institutions.

Figure 3. Simplified influenza treatment algorithm used to model the disease burden. Health states in the model are mutually exclusive. Transitions between states are identified with an arrow, a solid line indicates a reversible transition and unidirectional movement is shown via a dotted line. Health states are classified as Outpatient or Inpatient as shown in in the “Setting” row. Cost items are summarized below the setting. The diagnoses considered to be influenza-related per health state are listed below the diagram. ILI, Influenza-like Illness; ARI, Acute Respiratory Infection; SARI, Severe Acute Respiratory Infections; OTC, Over The Counter; GP, General Practitioner; ICU, Intensive Care Unit.