Survey Results

The Medicare Health Outcomes Survey (HOS) is an assessment of a health plan's ability to maintain or improve the physical and mental health functioning of its Medicare beneficiaries over a two-year period of time, using the best available science in functional status and health outcomes measurement. The survey is used as a way of measuring how the care provided by Medicare Advantage (MA) Plans is affecting the functional status of their enrollees.

The first cohort of baseline data was collected in 1998. Beginning in 2000, both a baseline cohort and a follow up cohort were collected. Most recently in 2007, Cohort 10 Baseline and Cohort 8 Follow Up data were collected. For further information, please refer to the survey administration timeline. The following table depicts general status information, including response rates, for the baseline and follow up cohorts administered to date.

Medicare HOS Survey Status Information¹

COHORT	DATE FIELDED	POPULATION	REPORTING UNITS (PLANS)2	SAMPLE SIZE	INVALID SURVEYS3	COMPLETED SURVEYS4	RESPONSE RATE5
Cohort 1 Baseline	May 1998	M+CO	287	279,135	7,196	167,096	61.4%
Cohort 1 Follow Up	April 2000	M+CO	188	89,332	1,203	75,593	85.8%
Cohort 2 Baseline	March 1999	M+CO PACE EverCare	312 20 6	301,184 4,225 5,015	8,829 435 655	194,378 1,752 1,226	66.5% 46.2% 28.1%
Cohort 2 Follow Up	June 2001	M+CO	160	88,468	1,539	73,015	84.0%
Cohort 3 Baseline	April 2000	M+CO PACE	306 20	298,883 3,831	7,662 564	208,655 1,672	71.6% 51.2%
Cohort 3 Follow Up	May 2002	M+CO	146	87,091	1,523	65,992	77.1%
Cohort 4 Baseline	May 2001	M+CO PACE	197 17	190,523 3,943	6,041 362	126,255 1,321	68.4% 36.9%
Cohort 4 Follow Up	May 2003	M+CO	152	71,549	951	55,480	78.6%
Cohort 5 Baseline	April 2002	M+CO PACE	177 20	171,504 4,834	5,963 710	106,168 1,385	64.1% 33.6%
Cohort 5 Follow Up	May 2004	MA	153	74,562	1,265	58,417	80.0%
Cohort 6 Baseline	April 2003	M+CO	163	161,409	5,579	100,669	64.6%
Cohort 6 Follow Up	May 2005	MA	154	69,865	854	56,075	81.3%
Cohort 7 Baseline	March 2004	MA	161	159,311	6,777	99,649	65.3%
Cohort 7 Follow Up	May 2006	MA	151	69,873	1,077	57,105	83.0%
Cohort 8 Baseline	April 2005	MA	164	162,902	6,966	101,588	65.1%
Cohort 8 Follow Up	May 2007	MA	TBD	TBD	TBD	TBD	TBD
Cohort 9 Baseline	April 2006	MA	203	188,515	7,725	120,708	66.8%
Cohort 10 Baseline	April 2007	MA	TBD	TBD	TBD	TBD	TBD

UPDATED August 2007

¹ Over the course of time, the refinement of the HOS measure has resulted in changes to the definition of a "completed survey." The information in the table provides a presentation of how a completed survey and response rate were calculated at the time of reporting for each of the baseline and follow up cohorts. Given that the definition of a completed survey has evolved over time, this table should not be utilized for response rate comparisons across the cohorts. If you are interested in comparative response rate information, please contact the Medicare HOS Information and Technical Support Line.

² For the baseline cohorts, the reporting units represent the individual plans sampled for the survey. However for the follow up cohorts, the reporting units have been adjusted to accommodate selected plan consolidations and service area reductions at the time of performance measurement reporting (which typically occurs in the year subsequent to the collection of the follow up data).

³ For the baseline cohorts, the invalid beneficiaries meet one of the following criteria: deceased; not enrolled in the MA Plan; have an incorrect address and phone number; or have a language barrier. For the follow up cohorts, the invalid beneficiaries meet one of the following criteria: not enrolled in the MA Plan; have an incorrect address and phone number; or have a language barrier.

⁴ In general, for Cohorts 1, 2, and 3 Baseline a completed survey is defined as a survey that has at least 80% of the questions answered. However, beginning with Cohort 1 Follow Up and Cohort 4 Baseline, a completed survey is defined as a survey that can be used to calculate physical or mental health summary scores.

⁵ Please note, invalid beneficiaries are removed from the denominator in the response rate calculations. In other words, Response Rate = [Number of Respondents/(Total Sample - Invalids)].

Performance Measurement Analytic Sample

After the administration of each follow up cohort, cohort specific performance measurement results are calculated. Seniors (age 65 or older) that had a calculatable physical component summary score or mental component summary score at baseline are eligible for performance measurement. However, some of these seniors belong to plans that went out of business or discontinued offering managed care between the baseline and follow up samples. Therefore, the Performance Measurement Analytic Sample is limited to those seniors who had calculatable physical or mental health summary scores at baseline and were still enrolled in the same participating MA Plan at the time of follow up. Seniors who become deceased between baseline and follow up are classified as "dead" for purposes of performance measurement. Additionally, a certain number of seniors will voluntarily disenroll from their plans between baseline and follow up. These seniors are classified as "voluntarily disenrolled" for purposes of performance measurement. Of the seniors sampled at the time of follow up, a certain percentage will be determined to be invalid for inclusion in the sample. These invalid seniors are: not enrolled in the MA Plan; have an incorrect address and phone number; or have a language barrier. Of the seniors eligible for inclusion in follow up, those that do not return a completed survey are designated as "non-respondents" and those that do return a completed survey are referred to as "respondents." The following table depicts the distribution of the Performance Measurement Analytic Sample presented in all performance measurement reports to date.

Medicare HOS Performance Measurement Distribution of Sample

COHORT	YEARS	REPORTING UNITS	ANALYTIC SAMPLE	VOLUNTARILY DISENROLLED	DEAD	FOLLOW UP INVALID SURVEYS	FOLLOW UP NON-RESPONDENTS	FOLLOW UP RESPONDENTS
Cohort 1	1998-2000	188	122,444	31,772	8,047	1,203	11,531	71,094
Cohort 2	1999-2001	160	124,835	33,226	8,930	1,179	12,758	68,742
Cohort 3	2000-2002	146	122,317	36,503	8,987	790	16,459	59,578
Cohort 4	2001-2003	152	95,565	24,589	6,998	392	12,950	50,636
Cohort 5	2002-2004	153	92,434	18,603	6,993	781	12,733	53,324
Cohort 6	2003-2005	154	90,154	13,550	6,739	854	12,936	56,075
Cohort 7	2004-2006	151	91,453	14,564	7,016	1,077	11,691	57,105

UPDATED August 2007

Calculating Performance Measurement Results

A performance measurement data set is created by merging a cohort's baseline and follow up data. Additionally, death information is incorporated into the performance measurement data set for those baseline respondents who died between baseline and follow up. The HOS performance measurement results are computed using a rigorous case mix/risk adjustment model.

There are six main categories of actual health outcomes used in the performance measurement analysis:

1. alive and physical health better;
2. alive and physical health the same;
3. dead or physical health worse;
4. mental health better;
5. mental health the same; and
6. mental health worse.

Each beneficiary is classified into one of the three physical health categories and one of the three mental health categories. In calculating expected outcomes, separate case mix models are warranted for death (which requires extensive case mix control), and for physical component summary scores and mental component summary scores (which do not require much case mix control). A series of eight different death models, three different physical health models, and three different mental health models are used, since all beneficiaries do not have data for all of the independent variables that could be used to calculate an expected score. In other words, each expected outcome for a beneficiary is derived from the best fit model, which is based on those variables for which the beneficiary has data. One model is used for each beneficiary, and there are no predictions made with missing data.

Beneficiary level results are aggregated to derive the plan, state, and HOS national percent better, same, and worse than expected values. Outliers are those plans that performed significantly better (i.e., better than expected) or significantly worse (i.e., worse than expected) when compared to the national average. The national average is based on all plans that participated in performance measurement. Plans can be outliers on a measure of physical health (which is based on death and the physical component summary score), or on a measure of mental health (which is based on the mental component summary score).

Analyses of the two-year performance measurement data have demonstrated that at the national level there is significant variation among Medicare health plans with respect to both physical and mental health outcomes. Research has identified difference in outcomes among specific groups of beneficiaries and potential opportunities to improve care. The following table depicts the overall performance measurement results by cohort.

Medicare HOS Performance Measurement Results

COHORT	YEARS	TOTAL NUMBER OF REPORTING UNITS	MENTAL HEALTH BETTER THAN EXPECTED	MENTAL HEALTH WORSE THAN EXPECTED	PHYSICAL HEALTH BETTER THAN EXPECTED	PHYSICAL HEALTH WORSE THAN EXPECTED
Cohort 1	1998-2000	188 plans	13 plans	15 plans	None	None
Cohort 2	1999-2001	160 plans	8 plans	5 plans	9 plans	5 plans
Cohort 3	2000-2002	146 plans	15 plans	4 plans	20 plans	1 plan
Cohort 4	2001-2003	152 plans	None	None	22 plans	1 plan
Cohort 5	2002-2004	153 plans	27 plans	3 plans	21 plans	None
Cohort 6	2003-2005	154 plans	18 plans	2 plans	None	None
Cohort 7	2004-2006	151 plans	5 plans	7 plans	2 plans	13 plans

UPDATED August 2007

A summary of the most recently available performance measurement results is available for download in a sample performance measurement report (PDF, 1.6 MB) . Included in the sample report is an overview of the methodology and design followed for sampling, data collection, and the cleaning, scoring, and analysis of the HOS data files.