Instructions for Analyzing Data from CAHPS Surveys

Purpose of this Document
CAHPS ® Surveys and Instructions
This document explains how the CAHPS Analysis Program works and how sponsors
and vendors can use the program to interpret the results of their CAHPS survey.
While the program was initially designed for the CAHPS Health Plan Survey, you can
use it to analyze data from any of the CAHPS surveys. For most CAHPS surveys, the
instructions include a document with analysis guidance specific to that survey.
The CAHPS Analysis Program
The goal of the CAHPS Analysis Program – often referred to as the CAHPS macro –
is to provide the user with a flexible way to analyze CAHPS survey data in order to
make valid comparisons of performance. Written in SAS, the CAHPS Analysis
Program is designed to assist CAHPS survey users in implementing two kinds of
statistical adjustments.
Comparing items and composites. CAHPS surveys collect consumers’ and patients’
reports and ratings of a number of dimensions of health care. Comparing performance
based on all the individual CAHPS survey items is a very complex task. Moreover,
individual survey items are often less reliable than multiple item combinations. To
simplify the interpretation of the data and enhance the reliability of the results,
questions that measure similar topics are grouped together. These groups of
questions, called composites, facilitate comparisons of performance across your unit
of analysis (e.g., health plan, medical practice, clinician). (Note: The instructions
available for each survey include a document that lists the items in that survey’s
reporting measures, i.e., composite measures and ratings.)
Adjusting for case mix. The CAHPS Team recommends that you adjust the survey
data for respondent age, education, and general health status. This makes it more
likely that reported differences are due to real differences in performance, rather than
differences in the characteristics of enrollees or patients.
Computing Requirements
The CAHPS Analysis Program was developed using SAS ® software. SAS is a data
management, analysis, and presentation product produced by the SAS Institute, which
is headquartered in Cary, North Carolina. The operation of SAS requires a Base
system, but a number of individual modules can be added to perform more complex
analyses and data manipulation.
The CAHPS Analysis Program requires Base SAS and the SAS/STAT module. Base
SAS, which is required to use any SAS product, provides the data manipulation, print
commands, simple plotting capabilities, and procedures for descriptive statistics. Base
SAS includes the CORE module. The SAS/STAT module adds several statistical
procedures for use by SAS. The CAHPS Analysis Program uses the SAS regression
procedure, PROC REG, to do part of its case-mix calculations. If case-mix
calculations will not be used, then the macro requires Base SAS only.
Instructions for Analyzing Data from CAHPS Surveys
Document No. 2015
Updated 4/2/12
Page 1