The public health value of vaccines beyond efficacy: methods, measures and outcomes.

BACKGROUND: Assessments of vaccine efficacy and safety capture only the minimum information needed for regulatory approval, rather than the full public health value of vaccines. Vaccine efficacy provides a measure of proportionate disease reduction, is usually limited to etiologically confirmed disease, and focuses on the direct protection of the vaccinated individual. Herein, we propose a broader scope of methods, measures and outcomes to evaluate the effectiveness and public health impact to be considered for evidence-informed policymaking in both pre- and post-licensure stages. DISCUSSION: Pre-licensure: Regulatory concerns dictate an individually randomised clinical trial. However, some circumstances (such as the West African Ebola epidemic) may require novel designs that could be considered valid for licensure by regulatory agencies. In addition, protocol-defined analytic plans for these studies should include clinical as well as etiologically confirmed endpoints (e.g. all cause hospitalisations, pneumonias, acute gastroenteritis and others as appropriate to the vaccine target), and should include vaccine-preventable disease incidence and 'number needed to vaccinate' as outcomes. Post-licensure: There is a central role for phase IV cluster randomised clinical trials that allows for estimation of population-level vaccine impact, including indirect, total and overall effects. Dynamic models should be prioritised over static models as the constant force of infection assumed in static models will usually underestimate the effectiveness and cost-effectiveness of the immunisation programme by underestimating indirect effects. The economic impact of vaccinations should incorporate health and non-health benefits of vaccination in both the vaccinated and unvaccinated populations, thus allowing for estimation of the net social value of vaccination. CONCLUSIONS: The full benefits of vaccination reach beyond direct prevention of etiologically confirmed disease and often extend across the life course of a vaccinated person, prevent outcomes in the wider community, stabilise health systems, promote health equity, and benefit local and national economies. The degree to which vaccinations provide broad public health benefits is stronger than for other preventive and curative interventions.

Disparities in hospital utilization in an urban county: use of local consumer marketing data for priority setting.

National data sets are often insufficient for priority setting by local public health systems and the communities they serve. We used marketing data to conduct an ecological analysis of hospital discharge rates in DeKalb County, Georgia, during 1996. Persons living in poorer areas had significantly higher discharge rates for the following conditions: hypertensive disease, blood-related conditions, pneumonia/influenza, diabetes, and chronic obstructive pulmonary diseases. Local marketing data helped identify conditions associated with higher hospital utilization in poorer areas of this urban county. This identification of priority issues informs plans for behavior modification, access to primary care and a healthy environment.

The burdens of uninsured hospitalizations in an urban county.

CONTEXT: Few data at the level of local health jurisdictions are available to characterize health problems specific to persons without health insurance. PRACTICE PATTERN EXAMINED: Hospitalization patterns of residents of DeKalb County, Georgia, who have no health insurance. DATA SOURCE: 1996 Georgia hospital discharge records for persons living within ZIP code areas included in or overlapping with DeKalb County. RESULTS: Of 67,156 hospital discharges, 6781 (10%) were for uninsured patients. Sixty-eight percent of uninsured hospitalizations took place in publicly owned and controlled hospitals, where uninsured persons represented 45% of all discharges. Charges associated with uninsured hospitalizations amounted to $51.3 million in 1996, of which $35.3 million (69%) was claimed by public hospitals. The uninsured were overrepresented in many diagnostic groups, including diabetes, injury and poisoning, chronic liver disease, skin disease, and infectious or parasitic disease. CONCLUSIONS: In DeKalb County, Georgia, the burden of uninsured hospitalizations falls disproportionately on the public sector. Policy initiatives are needed to more equitably share the burden of uninsured hospitalization with for-profit hospitals. Because the uninsured were overrepresented in several conditions, public health initiatives aimed at preventing these conditions should also be a priority.

Overseas screening for tuberculosis in immigrants and refugees to the United States: current status.

The number of reported cases of tuberculosis (TB) in foreign-born persons in the United States during 1995 was 8,042, 36% of the national total. The overseas screening of immigrants and refugee visa applicants, which relies on a chest radiograph and smear microscopy, is designed to identify future U.S. residents who have active TB or who are at high risk for TB. In this commentary, we summarize current policies and review retrospective evaluations of the screening system currently in place. The system appears to detect most persons who have active TB at the time of screening. However, active TB is actually diagnosed in < 15% of persons who are identified by screening as having suspected TB and who are evaluated in the United States. To improve the system, more sensitive and specific techniques as well as improved means of data transmission to state and local health departments are needed.

Comparison of the epidemiology and cost of Haemophilus influenzae type b disease in five western countries.

To determine and compare the cost of Haemophilus influenzae type b (Hib) disease in Australia, Finland, Israel, Switzerland and the United Kingdom a collaborative study was undertaken. The incidence of Hib disease varies in these 5 countries from 34 to 58.5 cases per 100,000 children less than 5 years of age. Although the incidence of meningitis in this age group is similar (between 18 and 26/100,000) in these countries, the incidence of epiglottitis varies from 0 to 22.7/100,000. The cost of hospitalization and the frequency of sequelae are similar for 4 of the 5 countries; however, the break even cost of a vaccination program to prevent 90% of Hib disease is estimated to vary from $22 to $84 per child (US$). Because of a lower incidence of Hib disease and lower cost for hospitalization, these costs are considerably less than those for the United States ($301.64 using similar calculations).