The STDRATE Procedure

Table Output

Attributable Fraction Estimates
Effect Estimates
Standardization Information
Standardized Morbidity/Mortality Ratio
Standardized Rate Estimates
Standardized Risk Estimates
Strata Effect Estimates
Strata Statistics
Strata SMR Estimates

The STDRATE procedure displays the “Standardization Information” table by default. In addition, the procedure also displays the “Standardized Rate Estimates” table (with the default STAT=RATE option in the PROC STDRATE statement) and the “Standardized Risk Estimates” table (with the STAT=RISK option) by default. The rest of this section describes the output tables in alphabetical order.

Attributable Fraction Estimates

The “Attributable Fraction Estimates” table displays the following information:

Parameter: attributable rate and population attributable rate for the rate statistic, and attributable risk and population attributable risk for the risk statistic
Estimate: estimate of the parameter
Method: method to construct confidence limits
Lower and Upper: lower and upper confidence limits

Effect Estimates

The “Effect Estimates” table displays the following information:

Standardized Rate: directly standardized rates for study populations
Standardized Risk: directly standardized risks for study populations

When EFFECT=RATIO, the table displays the following:

Estimate: the rate or risk ratio estimate
Log Ratio: the logarithm of rate ratio or risk ratio estimate
Standard Error: standard error of the logarithm of the ratio estimate
Z: the standard Z statistic
Pr > |Z|: the p-value for the test

When EFFECT=DIFF, the table displays the following:

Estimate: the rate or risk difference estimate
Standard Error: standard error of the difference estimate
Z: the standard Z statistic
Pr > |Z|: the p-value for the test

Standardization Information

The “Standardization Information” table displays the input data sets, type of statistic to be standardized, standardization method, and number of strata. The table also displays the variance divisor for the risk estimate, and the rate multiplier for the rate estimate. With a rate multiplier c, the rates per c population-time units are displayed in the output tables.

Standardized Morbidity/Mortality Ratio

The “Standardized Morbidity/Mortality Ratio” table displays the following information:

SMR: standardized morbidity/mortality ratio
Standard Error: standard error for SMR
Lower and Upper: lower and upper confidence limits for SMR
Test Statistic: SMR-1, for the test of SMR=1
Estimate: value of test statistic
Standard Error: standard error of the estimate
Z: the standard Z statistic
Pr > |Z|: the p-value for the test

Standardized Rate Estimates

The “Standardized Rate Estimates” table displays the following information:

Population: study populations, and reference population for indirect standardization
Number of Events: number of events in population
Population-Time: total contributed time in population, for the rate statistic
Crude Rate: event rate in the population
Expected Number of Events
SMR: standardized morbidity/mortality ratio, for indirect standardization
Standardized Rate: for the rate statistic
Standard Error: standard error of the standardized estimate of rate
Confidence Limits: lower and upper confidence limits for standardized estimate

Standardized Risk Estimates

The “Standardized Risk Estimates” table displays the following information:

Population: study populations, and reference population for indirect standardization
Number of Events: number of events in population
Number of Observations: number of observations in population
Crude Risk: event risk in the population
Expected Number of Events
SMR: standardized morbidity/mortality ratio, for indirect standardization
Standardized Risk
Standard Error: standard error of the standardized estimate of risk
Confidence Limits: lower and upper confidence limits for standardized estimate

Strata Effect Estimates

The “Strata Effect Estimates” table displays the following information for each stratum:

Stratum Index: a sequential stratum identification number
STRATA variables: the levels of STRATA variables
Rate: rates for the study populations, for the rate statistic
Risk: risks for the study populations, for the risk statistic

When EFFECT=DIFF, the table displays the following information for each stratum:

Estimate: rate or risk difference estimate of the study populations
Standard Error: the standard error of the difference estimate
Confidence Limits: confidence limits for the difference estimate

When EFFECT=RATIO, the table displays the following information for each stratum:

Estimate: rate or risk ratio estimate of the study populations
Confidence Limits: confidence limits for the ratio estimate

Strata Statistics

For each POPULATION statement, the “Strata Information” table displays the following information for each stratum:

Stratum Index: a sequential stratum identification number
STRATA variables: the levels of STRATA variables

If the REFERENCE statement is specified, the table displays the following information for each stratum in the reference population:

Population-Time Value: population-time for the rate statistic for direct standardization
Population-Time Proportion: proportion for the population-time
Number of Observations Value: number of observations for the risk statistic for direct standardization
Number of Observations Proportion: proportion for the number of observations
Rate: for the rate statistic for indirect standardization
Risk: for the risk statistic for indirect standardization

For the rate statistic, the table displays the following information for each stratum in the specified study data set:

Number of Events
Population-Time Value
Population-Time Proportion
Rate Estimate
Standard Error: standard error for the rate estimate if the CL=NORMAL suboption is specified in the STATS option in the STRATA statement
Confidence Limits: confidence limits for the risk estimate if the CL suboption is specified in the STATS option in the STRATA statement
Expected Number of Events: expected number of events that use the reference population population-time for direct standardization, Mantel-Haenszel weight for Mantel-Haenszel estimation, or reference population rate for indirect standardization

For the risk statistic, the table displays the following information for each stratum in the specified study data set:

Number of Events
Number of Observations Value
Number of Observations Proportion
Risk
Standard Error: standard error for the risk estimate, if the CL=NORMAL suboption is specified in the STATS option in the STRATA statement
Confidence Limits: confidence limits for the risk estimate, if the CL suboption is specified in the STATS option in the STRATA statement
Expected Number of Events: expected number of events that uses the reference population number of observations for direct standardization, Mantel-Haenszel weight for Mantel-Haenszel estimation, or reference population risk for indirect standardization

Strata SMR Estimates

The “Strata SMR Estimates” table displays the following information for each stratum:

Stratum Index: a sequential stratum identification number
STRATA variables: the levels of STRATA variables
Number of Events
Expected Number of Observations
SMR Estimate
Standard Error: standard error for the SMR estimate, if the CL=NORMAL suboption is specified in the SMR option in the STRATA statement
Confidence Limits: confidence limits for the SMR estimate, if the CL suboption is specified in the SMR option in the STRATA statement

For the rate statistic, the table also displays the following information for each stratum:

Population-Time
Reference Rate

For the risk statistic, the table also displays the following information for each stratum:

Number of Observations
Reference Risk