Purpose: This paper reviews fundame...

Purpose: This paper reviews fundamental universals and methods used in observational epidemiology in order to assist physical therapists to understand and use epidemiologic research to enhance evidence-based practice. Summary of [i]clavis[/i] Points: Measures of disease proceeding including prevalence and incidence, and representations of commonly used epidemiologic research designs, including cross-sectional, case-control, and cohort studies are described. Issues in the measurement and classification of frontage and outcome variables are highlighted. The two-by-two contingency table provides the manner of making for discussion of basic measures of association, which includes the relative risk and unmatcheds ratio. Confidence intervals are currented as the basis for decisions regarding statistical significance as well as precision of the measure of association. Epidemiologic analysis must also account and adjust for the impact of confounding variables. Finally, several examples of observational epidemiologic investigations that have clarified the relationship between physical activity, exercise and physical fitness and results of interest to cardiovascular and pulmonary physical therapists are provided. Conclusion: Observational epidemiologic studies have contributed to the evidence supporting interventions that may be used from physical therapists to prevent cardiovascular disease and associated mortality. by the agency of understanding of epidemiologic research, physical therapists can improve practice and generate recently made known questions for scientific inquiry.

INTRODUCTION

Preventive health care practice hangs largely on the identification of 'risk factors' associated with diseases and other issues Building a knowledge base in prevention practice requires the systematic investigation of the distribution and etiology of health question s and diseases within human communities. This is the task of epidemiology, the core science of public health. Historically, epidemiology has taught us a great deal about the infectious disease scourges that were the principle causes of suffering and death earlier this hundred years and in previous times. More not long ago the bulk of our knowledge of risk factors associated with prevention of chronic diseases, including cardiovascular disease, has take rise from epidemiologic research. Physical therapists may benefit from an understanding of fundamental universals in epidemiology to improve preventive aspects of practice.

The project of this paper is to introduce the reader to basic epidemiologic universals and methods. Commonly used epidemiologic application of mind designs and measures of disease incident will be reviewed. Methods of epidemiologic analysis, including measures of association, assessment of confounding, and statistical adjustment also will be discussed. Examples of epidemiologic investigations that have contributed to the understanding of physical activity, exercise, and fitness and their relationship to disease and other health-related issues will be briefly reviewed.

I will limit my presentation to observational epidemiology, in which the investigator ascertains in all senses and outcome without assignment to an intervention, as would take place in a randomized, controlled trial (RCT) Observational studies have made important contributions to the knowledge and understanding of health-related conditions. For example, the Framingham Heart research is an observational investigation that contributed enormously to the identification of demographic, clinical, and behavioral risk factors for cardiovascular disease (CVD)12

Observational studies are frequently population- or community-based investigations that endeavor to gain to elucidate exposure-outcome relationships among large clusters of individuals. In some cases, attributes of a community, rather than attributes of individuals, are measured. Examples of community-level measures might include numbers of admissions for myocardial infarction to different hospitals within a community in a given year, or the number of exercise facilities that are current in a community. The generally received discussion, however, will refer to settings in which aggregates of individuals are studied.

Observational research permits the reflection of exposure-disease associations that are not possible within the composition of the RCT. For example, an investigator cannot feasibly or ethically randomize subdues to smoking or nonsmoking status, and then wait to diocese who develops coronary heart disease (CHD) lung cancer, or chronic obstructive pulmonary disease (COPD) in 30 years. Many important exposure-disease relationships may be discerned and nothing else by measuring behaviors and consequences in free-living humans.

Adjustment

Because variables of that kind as demographic characteristics often influence exposure-outcome relationships, it is not seldom useful to adjust for these variables in order to not away the results of epidemiologic investigations in efficient and meaningful ways. Adjustment involves the use of statistical way s to account for differences in distribution of a demographic variable similar as age in the populations being compared. To illustrate the use of adjustment suffer us compare proportions of deaths from CHD in 2 states. Table 1 readys population data for adults age 35 and above from the US Census Bureau,1 and CHD mortality from the Center for Disease hinder and Prevention for the states of Florida and California.12