Supplementary Appendix to “Comparison of Trends in U.S. Health-Related Quality of Life over the 2000’s Using the SF-6D, HALex, EQ-5D, and EQ-5D Visual Analog Scale versus a Broader Set of Symptoms and Impairments” This Appendix gives sample sizes and covers three issues: the distribution of scores across measures, comparison of the health trend in MEPS data to the trend another national survey (NHIS) using the Survey Based Symptom/Impairment measure (SSI), and alternate mapping of SF-12 questions that changed in 2003, for both the SSI and SF-6D measures. Sample Sizes Table 1A shows sample sizes in each year of MEPS, for those with complete health data on all three measures available from 2000-2010, and those with complete data on measures available from 2000-2003. While those with incomplete HRQOL data were slightly younger, male, and nonwhite, and a higher proportion were missing in 2000 than in other years, rates of missingness differed little across years by age, gender, and race (results available from authors). Table 1: Sample Sizes Survey Sample 18+ Sample age 18+ that returned mailed health questionnaire* Percent of those returning health questionnaire with complete data on: SF-6D, SSI, and HALex VAS EQ-5D 2000 MEPS 17,555 15,502 90.6 86.3 96.5 2001 MEPS 23,686 20,966 96.0 95.7 97.7 2002 MEPS 27,275 24,249 96.3 95.5 98.3 2003 MEPS 23,511 20,821 97.2 95.4 98.3 2004 MEPS 23,819 20,973 95.5 2005 MEPS 23,527 20,680 95.2 2006 MEPS 23,786 20,832 95.4 2007 MEPS 21,745 19,067 95.3 2008 MEPS 23,162 20,526 95.3 2009 MEPS 25,998 23,171 95.1 2010 MEPS 23,422 20,802 95.4 *MEPS survey weights account for this non-response to the entire health questionnaire, but not for nonresponse to particular questions that prevent the calculation of summary health measures. Distribution of Scores Across Measures The distribution of scores on each health measure is shown in Figure 1A. While all measures had some lumping of scores at the high end, the HALex and EQ-5D had the least variation in scores, and the SF-6D and VAS had the widest variation. The distribution of the SSI measure was in between that of these other measures. .6 SSI .8 1 .5 0 .1 .2 .3 Fraction .2 .4 .6 SF6D .8 1 -.5 0 .5 1 HALex .4 .3 .2 .1 0 0 .1 .2 .3 Fraction .4 .5 .4 .5 .2 Fraction .4 .5 .4 0 .1 .2 .3 Fraction .3 .2 0 .1 Fraction .4 .5 Figure 1A: Distribution of Scores on each Health Measure in Pooled 2000-2002 MEPS Data 0 .5 EQ5D 1 0 .2 .4 .6 VAS .8 1 2 Comparison to Trend in the National Health Interview Survey To test for consistency in SSI scores across two different national health surveys covering the same time period, we calculated SSI scores in both MEPS and the National Health Interview Survey (NHIS) using the set of impairments and symptoms available in NHIS. This required omitting only the questions on cognition, pain and energy from our original SSI scoring in MEPS. Figure 2A shows the trend in age-adjusted HRQOL scores across these surveys from 200 through 2010. While the trends show some small differences in variation over time, they are quite similar. Figure 2A: Comparison of HRQOL Trends in MEPS and NHIS, Age 18+ 0.90 0.88 Mean HRQOL Score 0.85 SSI in NHIS 0.83 SSI in MEPS 0.80 0.78 0.75 0.73 0.70 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 3 Alternate Mappings of Changed SF-12 Items The wording of questions for each health measure are given in Table 1A (end of Appendix). Three of the questions used our ‘survey-based symptom and impairment’ (SSI) approach were affected by a switch from SF-12 version 1 to version 2 in the MEPS data in 2003. In version 2, the response choice "a good bit of the time" was dropped for questions on anxiety, depression, and energy. In addition, the wording of the depression question was changed from “downhearted and blue” to “downhearted and depressed”. The remainder of this appendix discusses our sensitivity analysis on the handling of these question changes. Alternate Mapping for the SSI Measure In constructing the SSI measure, we examined three different adjustments for this dropping of the “good bit” option from the questions on anxiety, depression, and energy. The first was to hold constant these three symptoms in 2003, adjusting prior years to account for this. This yielded scores very similar to the non-adjusted version shown in the main paper. The second was to follow the SF6D scoring and randomly assign those who responded ‘good bit’ in version 1 to the adjacent categories (‘most’ and ‘some’). The third was to examine the existing distribution of responses to these categories in each year and assign those who responded ‘good bit’ to the adjacent categories in that same proportion. For example, in 2000, 41% reported feeling calm ‘most of the time’ and 17% ‘some of the time’, indicating that only 28% of responses to these two categories were in the ‘some’ category. Thus, in years prior to 2003, we assigned 28% of those who reported ‘good bit’ on this question to the ‘some’ category, which classified them as ‘anxious’ on our dichotomous variable, and the remainder were assigned to the ‘most’ category, where they remained classified as non-anxious. The same method was used to reassign pre-2003 ‘good bit’ responses to the energy question. This method was not tested for the depression question since its wording changed in version 2, which could affect the distribution of responses in a manner difficult to account for. As shown by the black lines in Figures 3A and 4A, this adjustment raised anxiety rates and reduced low energy rates rates prior to 2003. The resulting drop in anxiety and rise in low energy in 2003 appeared too dramatic. Thus, our first approach of holding these things constant in 2003 appears to be a better approximation of what happened than our attempts to redistribute scores. The random assignment adjustment had a less dramatic effect, more similar to assuming no change in these items in 2003. Given this similarity and the fact that it is safest to assume no change in depressive symptoms due to the change in question wording, it is reasonable to also assume no change for anxiety and low energy in the SSI scoring. Because the combined effect of assuming no change in these items was almost identical to making no adjustment for the question changes, we show the unadjusted version in the main paper. 4 Figure 3A: Prevalence of Anxious Symptoms for SSI Measure Using Alternate Mappings for these Items to Adjust for Change to SF-6D Version 2 in 2003 Figure 4A: Prevalence of Low Energy for SSI Measure Using Alternate Mappings for these to Adjust for Change to SF-6D Version 2 in 2003 Items note: scores in figure not shown all the way through 2010 since focus is on period surrounding 2003 question change. Alternate Mappings for the SF-6D Measure The main paper shows the standard scoring distributed by SF-6D developers for use with each version of the SF-12. This scoring reassigns responses to role model questions from SF-12v2 to try to match to the dichotomous response categories in SF-12v1 version. All those responding in version 2 that they had any problems (a little of the time, some of the time, most of the time, or all 5 of the time) were assigned as having problems (to match ‘yes’ in version 1), resulting in a higher prevalence of role performance problems in 2003 and beyond. This explains the drop in SF-6D scores seen in 2003 in the main paper. For the depression and energy questions, the original SF-6D scoring randomly assigns those responding ‘a good bit of the time’ in SF-12v1 to adjacent response categories, to match SF-12v2. That adjustment has little effect due to the similarity of scores assigned to these adjacent categories. An alternate unpublished item mapping has also been developed for the SF-6D to account for differences between SF-12 versions 1 and 2 (program obtained via personal communication with Janel Hanmer). With this alternate mapping, for role questions, all version 2 categories are scored as version 1 ‘yes’ except “none of the time” and “a little of the time”. For depression, anxiety, and energy questions, “a good bit of the time” responses are assigned a scoring value that is the average of the “most” and “some” values. Figure 5A demonstrates the effect of this alternate mapping (though 2008 only, focus is on period surrounding 2003 question change). This adjustment avoids the drop in scores when switching to SF-2 version 2, slightly increasing rather than decreasing scores. It yields scores close to those that would be obtained if no change in SF-6D scores was assumed in 2003. Thus, SF-6D would not yield scores quite as much lower than other measures after 2003 if this alternate mapping were used. Figure 5A: Mean SF-6D Scores Among those Age 25 and Over Using Original Scoring and Alternate Mapping of SF-6D to Adjust Questions from SF-12 Versions 1 and 2 0.90 0.88 0.86 0.84 alternate mapping (Hanmer) 0.82 0.80 Assume no change in 2003 0.78 0.76 official scoring (shown in paper) 0.74 0.72 0.70 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 6 Table 1A: Symptom/Impairment Question wording Across Instruments Survey/Year in which Impairment/Symptom was Measured and Question Wording MEPS 2000-2010 Primary activity Social activity Self-care Moderate: Limited in ability to perform major activity (work at a job, do housework, or go to school) because of an impairment or a physical or mental health problem. Severe: completely unable to do this. Besides the limitations we just talked about, limited in participating in social, recreational, or family activities because of an impairment or a physical or mental health problem. Receive help or supervision with personal care such as bathing, dressing, or getting around the house because of an impairment or physical health problem. SF-6D During the past 4 weeks how much of the time have you been limited in the kind of work or other regular daily activities as a result of your physical health* How much of the time have you accomplished less than you would like in your work or other regular daily activities as a result of any emotional problems (such as feeling depressed or anxious)* During the past 4 weeks, how much of the time has your physical health or emotional problems interfered with your social activities (like visiting friends, relatives, etc.)? -- EQ-5D no problems with performing usual activities(e.g. work, study, housework, family or leisure activities)/some problems with performing usual activities/unable to perform usual activities HALex -- -- no problems with selfcare/some problems washing or dressing/unable to wash or dress self Receive help or supervision with personal care such as bathing, dressing, or getting around the house because of an impairment or physical health problem. Routine Needs Receive help or supervision using the telephone, paying bills, taking medications, preparing light meals, doing laundry, or going shopping Walking Moderate: Unable or some/a lot of difficulty walking a mile and/or some difficulty walking 3 blocks. Severe: Unable or a lot of difficulty walking 3 blocks. Bending Lifting Standing Reaching Dexterity -- Moderate activities, such as moving a table, pushing a vacuum cleaner, bowling, or playing golf Difficulty bending down or stooping from a standing position to pick up an object from the floor or tie a shoe (some/a lot/completely unable). Difficulty lifting 10 lbs (some/a lot/completely unable). Difficulty standing for 20 minutes (some/a lot/completely unable). Difficulty reaching overhead (some/a lot/completely unable). Difficulty using fingers to grasp (some/a lot/completely unable). -- -- Receive help or supervision using the telephone, paying bills, taking medications, preparing light meals, doing laundry, or going shopping no problems in walking about/some problems in walking about/confined to bed -- -- -- -- -- -- -- -- -- -- 8 Pain Pain interfered with normal work (including both work outside the home and housework) during the past 4 weeks Not at all, a little bit, moderately, quite a bit, extremely (SF-12). Depressive Symptoms Felt downhearted and blue during the past 4 weeks Anxiety Felt calm and peaceful during the past 4 weeks only some, a little, or none of the time (vs. a good bit, most or all of the time) none of the time, a little of the time, some of the time or a good bit of the time, most of the time, or all of the time (SF-12v1)* -- no pain or discomfort/ moderate pain or discomfort/extreme pain or discomfort -- not anxious or depressed/ moderately anxious or depressed/ extremely anxious or depressed -- -- -- -- -- -- -- (SF-12v1)* Energy Portion of the time person had a lot of energy during the past 4 weeks none of the time, a little of the time, some of the time or a good bit of the time, most of the time, or all of the time (SF-12v1)* Vision Difficulty seeing (with glasses or contacts, if used): some difficulty seeing or can not read ordinary newspaper print or can not recognize familiar people standing -- 9 two or three feet away or blind. Hearing Cognition Difficulty hearing (with hearing aid, if used): some difficulty hearing or can not hear some or most things people say or deaf. Experience confusion or memory loss such that it interferes with daily activities; have problems making decisions to the point that it interferes with daily activities; require supervision for own safety. -- -- -- -- -- -- *These 2 role items have been combined to form a 4-level SF-6D of: no limitations, limitations because of physical problems, limitations because of emotional problems, and limitations because of physical and emotional problems *These questions were part of the SF-12 but were not used in the scoring of the SF-6D. Changes to questions on depressive symptoms, anxiety, and energy in 2003 occurred as a result of the switch from SF12 version 1 to version 2: The ‘good bit of the time’ response option was omitted, affecting the distribution of responses into other categories. Depressive wording changed to ‘downhearted and depressed’. 10