The SURVEYREG Procedure

sets the confidence level for confidence limits. The value of the ALPHA= option must be between 0 and 1, and the default value is 0.05. A confidence level of produces % confidence limits. The default of ALPHA=0.05 produces 95% confidence limits.

specifies the SAS data set to be analyzed by PROC SURVEYREG. If you omit the DATA= option, the procedure uses the most recently created SAS data set.

treats missing values as a valid (nonmissing) category for all categorical variables, which include CLASS, STRATA, CLUSTER, and DOMAIN variables.

By default, if you do not specify the MISSING option, an observation is excluded from the analysis if it has a missing value. For more information, see the section Missing Values.

specifies the length of effect names in tables and output data sets to be n characters, where n is a value between 40 and 200. The default length is 40 characters.

treats that missing values in the variance computation as not missing completely at random (NOMCAR) for Taylor series variance estimation. When you specify this option, PROC SURVEYREG computes variance estimates by analyzing the nonmissing values as a domain or subpopulation, where the entire population includes both nonmissing and missing domains. For more information, see the section Missing Values.

By default, PROC SURVEYREG completely excludes an observation from analysis if that observation has a missing value, unless you specify the MISSING option. Note that the NOMCAR option has no effect on a classification variable when you specify the MISSING option, which treats missing values as a valid nonmissing level.

The NOMCAR option applies only to Taylor series variance estimation; it is ignored for replication methods.

specifies the sort order for the levels of the classification variables (which are specified in the CLASS statement).

This option also determines the sort order for the levels of DOMAIN variables.

This option applies to the levels for all classification variables, except when you use the (default) ORDER=FORMATTED option with numeric classification variables that have no explicit format. In that case, the levels of such variables are ordered by their internal value.

The ORDER= option can take the following values:

By default, ORDER=FORMATTED. For ORDER=FORMATTED and ORDER=INTERNAL, the sort order is machine-dependent.

For more information about sort order, see the chapter on the SORT procedure in the Base SAS Procedures Guide and the discussion of BY-group processing in SAS Language Reference: Concepts.

controls the plots that are produced through ODS Graphics.

When ODS Graphics is enabled and when the regression model depends on at most one continuous variable as a regressor, excluding the intercept, the PLOTS= option in the PROC SURVEYREG statement controls fit plots for the regression.

A plot-request identifies the plot, and a plot-option controls the appearance and content of the plot. You can specify plot-options in parentheses after a plot-request. A global-plot-option applies to all plots for which it is available unless it is altered by a specific plot-option. You can specify global-plot-options in parentheses after the PLOTS option.

When you specify only one plot-request, you can omit the parentheses around it. Here are a few examples of requesting plots:

plots=all
plots(weight=heatmap)=fit

When the regression model depends on at most one continuous variable as a regressor, excluding the intercept, PROC SURVEYREG provides a bubble plot or a heat map for model fitting. In a bubble plot, the bubble area is proportional to the weight of an observation. In a heat map, the heat color represents the sum of the weights at the corresponding location. The default plot depends on the number of observations in your data. That is, for a data set that contains 100 observations or less, a bubble plot is the default. For a data set that contains more than 100 observations, a heat map is the default.

ODS Graphics must be enabled before you can request a plot. For example:

ods graphics on;
proc surveyreg plots=fit;
   model height=weight;
run;

For more information about enabling and disabling ODS Graphics, see the section Enabling and Disabling ODS Graphics in Chapter 21: Statistical Graphics Using ODS.

When ODS Graphics is enabled, the ESTIMATE, LSMEANS, LSMESTIMATE, and SLICE statements can produce plots that are associated with their analyses. For information about these plots, see the corresponding sections of Chapter 19: Shared Concepts and Topics.

For general information about ODS Graphics, see Chapter 21: Statistical Graphics Using ODS.

Global Plot Option

A global-plot-option applies to all plots for which the option is available unless it is altered by a specific plot-option. You can specify the following global-plot-options:

Plot Requests

You can specify the following plot-requests:

specifies the sampling rate, which PROC SURVEYREG uses to compute a finite population correction for Taylor series variance estimation. This option is ignored for replication variance estimation methods.

If your sample design has multiple stages, you should specify the first-stage sampling rate, which is the ratio of the number of primary sampling units (PSUs) in the sample to the total number of PSUs in the population.

You can specify the sampling rate in either of the following ways:

You can specify sampling rates as numbers between 0 and 1. Or you can specify sampling rates in percentage form as numbers between 1 and 100, which PROC SURVEYREG converts to proportions. The procedure treats the value 1 as 100% instead of 1%.

For more information, see the section Specification of Population Totals and Sampling Rates.

If you do not specify either the RATE= or the TOTAL= option, the Taylor series variance estimation does not include a finite population correction. You cannot specify both the RATE= and TOTAL= options.

specifies the total number of primary sampling units (PSUs) in the study population. PROC SURVEYREG uses this information to compute a finite population correction for Taylor series variance estimation. This option is ignored for replication variance estimation methods.

You can specify the total number of PSUs in either of the following ways:

For more information, see the section Specification of Population Totals and Sampling Rates.

If you do not specify either the TOTAL= or the RATE= option, the Taylor series variance estimation does not include a finite population correction. You cannot specify both the TOTAL= and RATE= options.

specifies that class levels should be determined using no more than the first 16 characters of the formatted values of the CLASS, STRATA, and CLUSTER variables. When formatted values are longer than 16 characters, you can use this option in order to revert to the levels as determined in releases before SAS 9.

specifies the variance estimation method. PROC SURVEYREG provides the Taylor series method and the following replication (resampling) methods: balanced repeated replication (BRR), jackknife, and bootstrap.

Table 116.3 summarizes the available methods and method-options.

For VARMETHOD=BRR and VARMETHOD=JACKKNIFE, you can specify method-options in parentheses after the variance method name. For example:

varmethod=BRR(reps=60 outweights=myReplicateWeights)

By default, VARMETHOD=JACKKNIFE if you also specify a REPWEIGHTS statement; otherwise, VARMETHOD=TAYLOR by default.

You can specify the following methods: