SUPPORTING STATEMENT
Health and Diet Survey; Pet Food Labeling Survey
B. Statistical Methods (used for collection of information employing statistical methods)
Respondent Universe and Sampling Methods
The respondent universe for this collection of information will be non-institutionalized adults 18 and older, who speak English, who live in households with telephones in the 50 states and the District of Columbia, who have a cat or dog in the household, and who make decisions concerning the purchase and use of pet food. As of 1999, 94 percent of American households have telephone service.1 In 2007, approximately 57% of U.S. households owned at least one pet.2
A response rate of 34 percent was achieved in the collection of a subset of the information in this survey that was conducted in 2004. The agency expects to achieve a similar or higher response rate in this collection of information.
Procedures for the Collection of Information
2.1 Statistical methodology for collection and sample selection
The survey will be conducted using procedures outlined for the Health & Diet Survey (0910-0545).
2.2 Estimation Procedure
Refer to the Health & Diet Survey (0910-0545).
2.3 Degree of accuracy needed for the purpose described in the justification
For analyses of the Pet Food Labeling survey, the proposed sample size (1,000 adults) will provide a precision of approximately 1.9 to 3.1 percentage points at the 95 percent confidence level (Table 3). For analyses of subgroups, a standard error of 2.5 percentage points is usually acceptable. As shown in Table 3, this level of precision will also be achieved with the proposed sample size for many of the major demographic classifications (e.g., age, gender, education, and race).
Table 3. Sampling Error ( percentage points) at the 95 Percent Confidence Level for Different Sample Sizes
|
|
|
Proportion |
|
|
Sample Size |
0.1 (0.9) |
0.2 (0.8) |
0.3 (0.7) |
0.4 (0.6) |
0.5 (0.5) |
3000 |
1.1% |
1.4% |
1.6% |
1.8% |
1.8% |
2000 |
1.3% |
1.8% |
2.0% |
2.1% |
2.2% |
1800 |
1.4% |
1.8% |
2.1% |
2.3% |
2.3% |
1600 |
1.5% |
2.0% |
2.2% |
2.4% |
2.5% |
1400 |
1.6% |
2.1% |
2.4% |
2.6% |
2.6% |
1200 |
1.7% |
2.3% |
2.6% |
2.8% |
2.8% |
1000 |
1.9% |
2.5% |
2.8% |
3.0% |
3.1% |
800 |
2.1% |
2.8% |
3.2% |
3.4% |
3.5% |
600 |
2.4% |
3.2% |
3.7% |
3.9% |
4.0% |
400 |
2.9% |
3.9% |
4.5% |
4.8% |
4.9% |
200 |
4.2% |
5.5% |
6.4% |
6.8% |
6.9% |
2.4 Use of specialized sampling procedures
No specialized sampling procedures are required.
2.5 Use of periodic data collection cycles to reduce burden
This is a one-time data collection.
Refer to the Health & Diet Survey (0910-0545).
4. Test of Procedures or Methods to be Undertaken
Refer to the Health & Diet Survey (0910-0545).
5. Individuals Consulted on Statistical Aspects and Individuals Collecting and/or Analyzing Data
For the Pet Food Labeling survey, the contractor, Westat, Inc. will collect the information on behalf of the FDA as a task order under the Quick-Turn-Around Research Services contract. Martha Kudela, Ph.D., is the Senior Study Director for Market Facts, telephone 301-251-4382. Analysis of the pet food label usage information will be conducted primarily by staff on the Consumer Studies Team, Division of Market Studies, CFSAN, FDA, and coordinated by Conrad J. Choinière, PhD, telephone (301) 436-1844.
1 U.S. Census Bureau. 2002. Table 1126, Statistical Abstract of the United States: 2001. Washington, D.C.
2 American Veterinary Medical Association. 2007. U.S. Pet Ownership and Demographics Sourcebook.
| File Type | application/msword |
| File Title | SUPPORTING STATEMENT |
| Author | Jonna Capezzuto |
| Last Modified By | Jonna Capezzuto |
| File Modified | 2008-05-19 |
| File Created | 2008-05-19 |