Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 5

Define efficacy and effectiveness, and provide examples of both.

Use the following information to answer questions 6 and 7.

Emergency Medical Services (EMS) responses were made to 1,551 nonindustrial injuries resulting from falls. Of total falls, 869 (56%) occurred at home and 682 (44%) occurred elsewhere. The very young (4 years old) and the very old (80+ years) were the most vulnerable to falls. Persons over age 60 accounted for 44% of the total emergency calls for nonindustrial falls. On weekends, most injuries from falls occurred in the home. Time pattern analysis revealed that the greatest number of injuries from falls at home occurred in the late afternoon and evening, between 3:00 PM and midnight. Callers from three socioeconomic strata were identified from census tract information. Age and gender were tabulated for the three strata areas based on falls in the home. The greatest use of EMS was by those over 60 years of age in all three strata levels. Those aged 40–59 years in the low socioeconomic group and infants through 9 years of age in the low socioeconomic group were next highest users. The highest socioeconomic group had the lowest rates for each age group.27 The percentages given are out of total emergency EMS responses. Table 1 represents percentages of falls per total population based on the rates per 100,000 people.

• Population for the high socioeconomic group was 143,798.

• Population for the medium socioeconomic group was 249,381.

• Population for the low socioeconomic group was 138,413.

TABLE 1 Home Falls and Emergency Medical Service Response in the State of Washington

Age Group	High Socioeconomic Rate/100,000	Percentage of Total Population	Medium Socioeconomic Rate/100,000	Percentage of Total Population	Low Socioeconomic Rate/100,000	Percentage of Total Population
0–9	87.95	3.8	199.88	6.4	260.24	2.9
10–19	35.94	4.8	87.43	6.7	104.81	2.9
20–39	29.69	8.2	60.77	14.9	104.76	9.1
40–59	60.66	6.8	168.42	9.7	288.89	5.1
60+	444.05	3.4	355.18	9.3	420.66	5.9
TOTAL	—	27.05	—	46.91	—	26.04

Step 1 of 2

While doing evaluation of control as well as prevention program, effectiveness and efficacy of the concerned program is considered. Efficacy is defined as an ability of a given program for producing desired effect of the individuals that participate in that program as compared to those who not.

Effectiveness is defined as an ability of a program in producing benefits in those that are offered with the program. Like for example whenever a strict intervention program is prepared to help in the process of recovery of heart patients.

The people who can comply to the program possess better recoveries rather than those that do not then such program is said to be efficacious but when the compliance becomes low due to the cost, amount as well as food type that are involved in that program then the program is said not to be effective.