The SURVEYFREQ Procedure
| Displayed Output |
Data Summary Table
The "Data Summary" table provides information about the input data set and the sample design. PROC SURVEYFREQ displays this table unless you specify the NOSUMMARY option in the PROC SURVEYFREQ statement.
The "Data Summary" table displays the total number of valid observations. To be considered valid, an observation must have a nonmissing, positive sampling weight value if you specify a WEIGHT statement. If you do not specify the MISSING option, a valid observation must also have nonmissing values for all STRATA and CLUSTER variables. The number of valid observations can differ from the number of nonmissing observations for an individual table request, which the procedure displays in the frequency or crosstabulation tables. See the section Missing Values for more information.
PROC SURVEYFREQ displays the following information in the "Data Summary" table:
Number of Strata, if you specify a STRATA statement
Number of Clusters, if you specify a CLUSTER statement
Number of Observations, which is the total number of valid observations
Sum of Weights, which is the sum over all valid observations, if you specify a WEIGHT or REPWEIGHTS statement
Stratum Information Table
If you specify the LIST option in the STRATA statement, PROC SURVEYFREQ displays a "Stratum Information" table. This table provides the following information for each stratum:
Stratum Index, which is a sequential stratum identification number
STRATA variables, which list the levels of STRATA variables for the stratum
Number of Observations, which is the number of valid observations in the stratum
Population Total for the stratum, if you specify the TOTAL= option
Sampling Rate for the stratum, if you specify the TOTAL= or RATE= option. If you specify the TOTAL= option, the sampling rate is based on the number of valid observations in the stratum.
Number of Clusters, which is the number of clusters in the stratum, if you specify a CLUSTER statement
Variance Estimation Table
If you specify the VARMETHOD=BRR, VARMETHOD=JACKKNIFE, or NOMCAR option in the PROC SURVEYFREQ statement, the procedure displays a "Variance Estimation" table. If you do not specify any of these options, the procedure creates a "Variance Estimation" table but does not display it. You can store this nondisplayed table in an output data set by using the Output Delivery System (ODS). See the section ODS Table Names for more information.
The "Variance Estimation" table provides the following information:
Method, which is the variance estimation method—Taylor Series, Balanced Repeated Replication, or Jackknife
Replicate Weights input data set name, if you provide replicate weights with a REPWEIGHTS statement
Number of Replicates, for VARMETHOD=BRR or VARMETHOD=JACKKNIFE
Hadamard Data Set name, if you specify the HADAMARD= method-option for VARMETHOD=BRR
Fay Coefficient, if you specify the FAY method-option for VARMETHOD=BRR
Missing Levels Included (MISSING), if you specify the MISSING option
Missing Levels Included (NOMCAR), if you specify the NOMCAR option
Hadamard Matrix
If you specify the PRINTH method-option for VARMETHOD=BRR, PROC SURVEYFREQ displays the Hadamard matrix used to construct replicates for BRR variance estimation. If you provide a Hadamard matrix with the HADAMARD= method-option for VARMETHOD=BRR but the procedure does not use the entire matrix, the procedure displays only the rows and columns that are actually used to construct replicates.
One-Way Frequency Tables
PROC SURVEYFREQ displays one-way frequency tables for all one-way table requests in the TABLES statements, unless you specify the NOPRINT option in the TABLES statement. A one-way table shows the sample frequency distribution of a single variable, and provides estimates for its population distribution in terms of totals and proportions.
If you request a one-way table without specifying options, PROC SURVEYFREQ displays the following information for each level of the variable:
Frequency count, which is the number of sample observations in the level
Weighted Frequency, which estimates the population total for the level
Standard Deviation of Weighted Frequency
Percent, which estimates the population proportion for the level
Standard Error of Percent
The one-way table displays weighted frequencies if your analysis includes a WEIGHT or REPWEIGHTS statement, or if you specify the WTFREQ option in the TABLES statement.
The one-way table also displays the Frequency Missing, which is the number of observations with missing values.
You can suppress the frequency counts by specifying the NOFREQ option in the TABLES statement. Also, the NOWT option suppresses the weighted frequencies and their standard deviations. The NOPERCENT option suppresses the percentages and their standard errors. The NOSTD option suppresses the standard errors of the percentages and the standard deviations of the weighted frequencies. The NOTOTAL option suppresses the total row of the one-way table.
PROC SURVEYFREQ optionally displays the following information in a one-way table:
Variance of Weighted Frequency, if you specify the VARWT option
Confidence Limits for Weighted Frequency, if you specify the CLWT option
Coefficient of Variation for Weighted Frequency, if you specify the CVWT option
Test Percent, if you specify the TESTP= option
Variance of Percent, if you specify the VAR option
Confidence Limits for Percent, if you specify the CL option
Coefficient of Variation for Percent, if you specify the CV option
Design Effect for Percent, if you specify the DEFF option
Crosstabulation Tables
PROC SURVEYFREQ displays all table requests in the TABLES statements, unless you specify the NOPRINT option in the TABLES statement. For two-way to multiway crosstabulation tables, the values of the last variable in the table request form the table columns. The values of the next-to-last variable form the rows. Each level (or combination of levels) of the other variables forms one layer. PROC SURVEYFREQ produces a separate two-way crosstabulation table for each layer of a multiway table.
For each layer, the crosstabulation table displays the row and column variable names and values (levels). Each two-way table lists levels of the column variable within each level of the row variable.
By default, the procedure displays all levels of the column variable within each level of the row variables, including any column variable levels with zero frequency for that row. For multiway tables, the procedure displays all levels of the row variable for each layer of the table by default, including any row levels with zero frequency for that layer. You can suppress the display of zero frequency levels by specifying the NOSPARSE option.
If you request a crosstabulation table without specifying options, the table displays the following information for each combination of variable levels (table cell):
Frequency, which is the number of sample observations in the table cell
Weighted Frequency, which estimates the population total for the table cell
Standard Deviation of Weighted Frequency
Percent, which estimates the population proportion for the table cell
Standard Error of Percent
The two-way table displays weighted frequencies if your analysis includes a WEIGHT or REPWEIGHTS statement, or if you specify the WTFREQ option in the TABLES statement.
The two-way table also displays the Frequency Missing, which is the number of observations with missing values.
You can suppress the frequency counts by specifying the NOFREQ option in the TABLES statement. Also, the NOWT option suppresses the weighted frequencies and their standard deviations. The NOPERCENT option suppresses all percentages and their standard errors. The NOCELLPERCENT option suppresses overall cell percentages and their standard errors, but displays any other percentages (and standard errors) that you request, such as row or column percentages. The NOSTD option suppresses the standard errors of the percentages and the standard deviations of the weighted frequencies. The NOTOTAL option suppresses the row totals and column totals, as well as the overall total.
PROC SURVEYFREQ optionally displays the following information in a two-way table:
Expected Weighted Frequency, if you specify the EXPECTED option
Variance of Weighted Frequency, if you specify the VARWT option
Confidence Limits for Weighted Frequency, if you specify the CLWT option
Coefficient of Variation for Weighted Frequency, if you specify the CVWT option
Variance of Percent, if you specify the VAR option
Confidence Limits for Percent, if you specify the CL option
Coefficient of Variation for Percent, if you specify the CV option
Design Effect for Percent, if you specify the DEFF option
Row Percent, which estimates the population proportion of the row total, if you specify the ROW option
Standard Error of Row Percent, if you specify the ROW option
Variance of Row Percent, if you specify the VAR option and the ROW option
Confidence Limits for Row Percent, if you specify the CL option and the ROW option
Coefficient of Variation for Row Percent, if you specify the CV option and the ROW option
Design Effect for Row Percent, if you specify the ROW(DEFF) option
Column Percent, which estimates the population proportion of the column total, if you specify the COL option
Standard Error of Column Percent, if you specify the COL option
Variance of Column Percent, if you specify the VAR option and the COL option
Confidence Limits for Column Percent, if you specify the CL option and the COL option
Coefficient of Variation for Column Percent, if you specify the CV option and the COL option
Design Effects for Column Percent, if you specify the COL(DEFF) option
Statistical Tests
If you specify the CHISQ option for the Rao-Scott chi-square test or the LRCHISQ option for the Rao-Scott likelihood ratio chi-square test, PROC SURVEYFREQ displays the following information:
Pearson Chi-Square, if you specify the CHISQ option
Likelihood Ratio Chi-Square, if you specify the LRCHISQ option
Design Correction
Rao-Scott Chi-Square, by default or if you specify the FIRSTORDER option
First-Order Chi-Square, if you specify the SECONDORDER option
Second-Order Chi-Square, if you specify the SECONDORDER option
DF, which is the degrees of freedom for the chi-square test
Pr > ChiSq, which is the p-value for the chi-square test
F Value
Num DF, which is the numerator degrees of freedom for F
Den DF, which is the denominator degrees of freedom for F
Pr > F, which is the p-value for the F test
If you specify the WCHISQ option for the Wald chi-square test or the WLLCHISQ option for the Wald log-linear chi-square test, PROC SURVEYFREQ displays the following information:
Wald Chi-Square, if you specify the WCHISQ option
Wald Log-Linear Chi-Square, if you specify the WLLCHISQ option
F Value
Num DF, which is the numerator degrees of freedom for F
Den DF, which is the denominator degrees of freedom for F
Pr > F, which is the p-value for the F test
Adjusted F Value, for tables larger than
Num DF, which is the numerator degrees of freedom for Adjusted F
Den DF, which is the denominator degrees of freedom for Adjusted F
Pr > Adj F, which is the p-value for the Adjusted F test
Risks and Risk Difference
If you specify the RISK option in the TABLES statement for a table, PROC SURVEYFREQ displays "Column 1 Risk Estimates" and "Column 2 Risk Estimates" tables. You can display only column 1 or column 2 risks by specifying the RISK1 or RISK2 option, respectively.
The "Risk Estimates" table displays the following information for Row 1, Row 2, Total, and Difference:
Row, which identifies the risk as Row 1, Row 2, Total, or Difference
Risk estimate
Standard Error
Confidence Limits
In the "Column 1 Risk Estimates" table, the row 1 risk is the column 1 percentage of row 1. The row 2 risk is the column 1 percentage of row 2, and the total risk is the column 1 percentage of the entire table. The risk difference is the row 1 risk minus the row 2 risk. In the "Column 2 Risk Estimates" table, these computations are based on column 2.
Odds Ratio and Relative Risks
If you specify the OR option in the TABLES statement for a table, PROC SURVEYFREQ displays the "Odds Ratio" table. This table includes the following information:
Statistic, which identifies the statistic as the Odds Ratio, the Column 1 Relative Risk, or the Column 2 Relative Risk
Estimate
Confidence Limits