Applying a new conceptual framework to evaluate tuberculosis surveillance and action performance and measure the costs, Hillsborough County, Florida, 2002

Abstract

Purpose

Tuberculosis (TB) elimination is an important US public health goal and improving the performance of TB surveillance and action and reducing the costs will help achieve it. But, there exists the need to better evaluate the performance and measure the costs.

Methods

We pilot tested an evaluation strategy in Hillsborough County, Florida using a conceptual framework of TB surveillance and action with eight core and four support activities. To evaluate performance, we developed indicators and validated their accuracy, usefulness, and measurability. To measure the costs, we obtained financial information.

Results

In 2001, Hillsborough County reported 78 (7%) of the 1145 Florida TB cases. Nineteen (24%) were previously arrested. While 13 (68%) of the 19 were incarcerated during the 2 years prior to being reported, only 1 (5%) of 19 was reported from the jail. From 111 TB suspects, 219 (25%) of 894 sputum specimens were inadequately collected. Of the $1.08 million annual budget, 22% went for surveillance, 29% for support, and 49% for action.

Conclusions

This conceptual framework allowed measurement of TB surveillance and action performance and cost. The evaluation performed using it revealed missed opportunities for detection of TB cases and wasted resources. This conceptual framework could serve as a model for evaluation of TB surveillance and action.

Introduction

Tuberculosis (TB) elimination in the United States remains an important public health goal. The Institute of Medicine (IOM) report Ending Neglect: The Elimination of Tuberculosis in the United States reviewed the lessons learned from the neglect of TB between the 1960s and early 1990s (1). This report identified five areas requiring decisive action to achieve TB elimination in the United States by 2010:

• Maintain control of TB incidence;

• Speed the decline;

• Develop new tools;

• Increase involvement in global efforts; and

• Mobilize and sustain public support.

The first priority area identified by the IOM report—maintain control of TB incidence—includes one objective to maintain and enhance local, state, and national public health surveillance for TB. Public health surveillance can be defined as the ongoing, systematic, collection, analysis, interpretation, and dissemination of data of a health event for use in public health action to reduce morbidity and mortality and to improve health (2).

Evaluating the performance of public health surveillance and action and measuring the costs are necessary to ensure that the health events are surveyed and acted upon effectively and efficiently. Further, evaluation has now become an essential component of public health practice (3).

A clear understanding of program processes, performance, outcomes, and costs can demonstrate the value added from the resources expended. This is particularly important in today's climate where public health must be maximized for efficient resource allocation (4). Activity-based costing is the practice of assigning financial costs to specific activity categories that lie within a larger process. This allows a full understanding of the costs of each activity within the process (5). Using activity-based costing, the total cost of TB surveillance and action can be captured and allocated to predefined activities. TB programs could then understand the cost of each activity, and TB program managers can then use these financial data to more efficiently allocate resources to enhance program effectiveness.

For the past 10 years, Florida has ranked fourth in the United States for the number of reported TB cases per year. In 2002, California (with 3169 TB cases), Texas (with 1550), and New York (with 1435) ranked higher than Florida (with 1086 cases). In addition, the rate of decline in TB incidence has slowed. Florida's TB incidence rate declined only 48.8% from 1992 to 2002. During the same period, New York experienced a 70% decline, Texas experienced a 50% decline, and California experienced a 48.3% decline.

Hillsborough County, Florida, has a population of approximately 1 million and includes the city of Tampa. Considered one of the “Big Six” counties in Florida in terms of its population size and TB incidence, in 2001 Hillsborough County reported 78 TB cases, with an incidence rate of 7.6 per 100,000; 36% greater than the national average of 5.6 (6).

The Hillsborough County Health Department (HCHD) TB program has 25 staff that provide services to all suspected and confirmed TB patients. Its goals are to identify and treat patients with active TB; find, screen, and treat contacts of active TB; and screen and treat high-risk populations for latent TB infection (LTBI). The development and implementation of a simple and standardized tool for evaluating the performance of TB public health surveillance and action and measuring their costs will help achieve these goals.

Historically, the evaluation of public health surveillance has focused on assessing the surveillance system's core attributes of sensitivity, simplicity, flexibility, data quality, acceptability, predictive value positive, representativeness, timeliness, and stability (2). However, this approach does not evaluate the public health action that ensues as a result of the surveillance data gathered. Further, it does not allow for activity-based costing. The purpose of this study was to apply a new conceptual framework for public health surveillance and action to a county health department TB program activities, and use this framework to evaluate TB surveillance and action performance and measure their costs.