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Findings Appendix


Table A1: Demographic Profiles Of Each Group Of Newly Insured, Still Insured, and Remaining Uninsured Californians
NEWLY INSURED IN 2016

(15%)

STILL INSURED IN 2016

(57%)

REMAINING UNINSURED IN 2016

(28%)

AGE 19-29 32% 21% 24%
30-49 35% 42% 55%
50-64 32% 31% 19%
65+ 2% 6% 1%
RACE White non-Hispanic 19% 33% 18%
Black non-Hispanic 8% 5% 4%
Other non-Hispanic 26% 13% 9%
Hispanic 59% 48% 67%
Hispanic, eligible 30% 40% 33%
GENDER Male 57% 51% 53%
Female 43% 49% 47%
LENGTH OF TIME UNINSURED PRIOR TO ACA 2 months to less than a year 6% 15% 8%
1 year to less than 2 years 6% 16% 12%
2 years or more 43% 49% 39%
Never had insurance 45% 21% 41%
EMPLOYMENT Employed 58% 67% 57%
Unemployed 14% 11% 19%
A student, retired, on disability, or stay at home parent 26% 21% 24%
EDUCATION High school or less 52% 51% 72%
Some college 31% 32% 22%
College or more 13% 16% 6%
HEALTH STATUS Excellent/ Very good/ Good 61% 59% 70%
Fair/ Poor 39% 41% 30%
MARITAL STATUS Married 22% 42% 42%
Not married 77% 57% 58%
FAMILY INCOME Less than 138% FPL 56% 51% 56%
Between 138% – 400% FPL 41% 37% 37%
Over 400% FPL 3% 11% 6%
DEBILITATING CHRONIC CONDITION Yes 12% 20% 8%
No 87% 79% 92%
PERSONALLY CONTACTED Yes, been contacted 30% 32% 15%
No, have not been contacted 70% 67% 84%

Wave 4 Attrition Appendix

A unique consideration for panel surveys such as the Kaiser Family Foundation California Longitudinal Panel Survey is whether those who participate in subsequent waves are different in terms of their attitudes or demographics than those who refuse to participate again or were unable to be re-contacted. Of the total 2,001 respondents who completed Wave 1, 1,219 participated in Wave 2, 1,105 completed Wave 3, and 1,001 completed Wave 4. These completion rates are within an expected range given that the uninsured are already a difficult to reach population since many are lower income, younger, undocumented immigrants, and members of racial/ethnic minority groups, and may change phone numbers or move more often than the public at large. After data collection was complete, data from Wave 1 and Wave 4 were compared to evaluate the impact of some respondents not completing Wave 4, referred to as attrition. Wave 4 respondents included those who completed all four waves (n=764) as well as those who completed Waves 1 and 4 only (n=52), those who completed Waves 1, 2, and 4 (n=87), and those who completed Waves 1, 3, and 4 (n=98). The analysis was designed to assess whether: (1) The makeup of respondents differed systematically between the waves; and (2) whether these differences correspond with bias as far as the study’s substantive questions.

As detailed below in Table A1, we compared Wave 1 question responses for the total Wave 1 and Wave 4 samples to assess whether Wave 4 consists of respondents who answered Wave 1 differently than the full Wave 1 sample. The table also includes comparisons for the subsample of Wave 4 respondents who have completed all four waves. The weighted columns indicate whether any differences in sample characteristics and substantive responses were minimized through Wave 4 weighting. The comparison indicates that the greatest difference between the complete Wave 1 sample and the Wave 4 sample centers on respondents with lower educational attainment (8 percentage points less in Wave 4), Spanish speaking (7 percentage points less in Wave 4), undocumented respondents (6 percentage points less in Wave 4), male respondents (5 percentage points less in Wave 4), cell phone respondents (6 percentage points less in Wave 4), and respondents under age 30 (4 percentage points less in Wave 4), along with an increase in the share of white respondents as well as a decrease in the share of Hispanic respondents (6 and 7 percentage points, respectively). This seems to indicate that the harder-to-reach (namely undocumented), more transient (cell phone), and younger respondents were slightly less likely to be reached and to complete the Wave 4 interview. These differences are similar to the differences among those who completed all four waves of the survey. However, these demographic differences between the samples did not translate into meaningful differences on the questions of self-reported party identification, self-reported health status, or whether respondents reported having a usual source of care at Wave 1. Furthermore, once the sample was weighted as it would be in any case, only slight demographic differences remained. The variables not included in the weighting were hardly affected by weighting, or became more similar to Wave 1 (Table A2). Overall, this analysis finds fairly small observable differences between Wave 4 respondents and the full Wave 1 sample as far as Wave 1 responses. Attrition does not appear to introduce significant bias, and most differences are addressed by weighting (that was specifically designed to match the Wave 1 sample, adding parameters such as language of interview and income relative to the federal poverty level (FPL)).

Table A2: Wave 1 To Wave 4 Sample Comparisons For Wave 1 Questions (Weighted And Unweighted)
Unweighted Weighted
Wave 1
(n=2001)
Completed Wave 4
(n=1001)
Completed all 4 Waves (n=764) Percentage Point
Difference
(W1 – W4 Total)
Wave 1 Completed Wave 4 Completed all 4 Waves Percentage Point
Difference
(W1 – W4 Total)
Gender
Male 48% 43% 41% 5 54% 53% 50% 1
Female 52% 57% 59% -5 46% 47% 50% -1
Race/ Ethnicity
White 27% 33% 36% -6 26% 27% 28% -1
Black 7% 8% 8% -1 5% 5% 5% 0
Hispanic 58% 51% 48% 7 56% 55% 54% 1
Other Race 8% 8% 8% 0 13% 12% 13% 1
Age
19 to 29 23% 19% 17% 4 33% 31% 28% 2
30 to 39 21% 19% 19% 2 24% 23% 24% 1
40 to 49 22% 20% 19% 2 21% 22% 23% -1
50 to 64 35% 43% 45% -8 22% 24% 25% -2
Education
HS or less 57% 49% 47% 8 58% 57% 57% 1
Some college 28% 33% 34% -5 29% 29% 29% 0
College Grad+ 15% 17% 18% -2 12% 13% 14% -1
Phone status
Landline 49% 55% 56% -6 42% 45% 48% -3
Cell 51% 45% 44% 6 58% 55% 52% 3
Marital status
Married 33% 34% 33% -1 37% 38% 37% -1
Not Married 67% 65% 67% 2 62% 62% 63% 0
Family income
<138% FPL 60% 57% 57% 3 52% 53% 55% -1
138%-400% FPL 30% 33% 33% -3 36% 34% 33% 2
400%+ FPL 5% 6% 6% -1 7% 7% 6% 0
Language of interview
English 63% 70% 72% -7 65% 66% 64% -1
Spanish 37% 30% 28% 7 35% 34% 34% 1
Table A3: Wave 1 And Wave 4 Sample Comparisons For Wave 1 Questions Not Used In Weighting (Weighted And Unweighted)
Unweighted Weighted
Wave 1
(n=2001)
Completed Wave 4
(n=1001)
Completed all 4 Waves (n=764) Percentage Point
Difference
(W1 – W4 Total)
Wave 1 Completed Wave 4 Completed all 4 Waves Percentage Point
Difference
(W1 – W4 Total)
Resident Status
Citizen/ legal immigrant 79% 85% 86% -6 78% 81% 81% -3
Undocumented immigrant 20% 14% 13% 6 21% 18% 18% 3
Party Identification
Republican 11% 13% 13% -2 11% 11% 12% 0
Democrat 35% 39% 39% -4 32% 34% 34% -2
Independent 35% 32% 32% 3 37% 36% 35% 1
Other 9% 8% 8% 1 9% 9% 9% 0
Length of time uninsured prior to ACA
2 months to less than a year 12% 11% 11% 1 13% 11% 11% 2
1 year to less than 2 years 12% 12% 13% 0 14% 13% 15% 1
2 years or more 48% 53% 55% -5 44% 45% 45% -1
Never insured 28% 23% 21% 5 29% 30% 30% -1
Self-reported health status
Excellent/Very good/Good 59% 60% 60% -1 62% 62% 64% 0
Fair/Poor 41% 40% 40% 1 38% 37% 36% -1
Debilitating Chronic Condition
Yes 16% 19% 21% -3 13% 15% 15% -2
No 84% 81% 79% 3 87% 84% 85% 3
Usual place for care
Yes 61% 63% 63% -2 56% 57% 57% -1
No 39% 36% 37% 3 43% 42% 43% 1

An indicator consistent with this observation is the mean Wave 1 Weight of the Wave 4 sample. This value, 0.979 (SE=0.031), indicates that the measure to which Wave 4 respondents further accentuated Wave 1 non-response patterns (corresponding with smaller weights) was relatively small, about 2%. For those who responded to all four waves, this value was slightly smaller (0.973; SE=0.036), but still indicative of overall similarity between responders and non-responders.

We also compared the unweighted demographics for those who completed Wave 4 with those who didn’t (a typical nonresponse analysis) and there are some differences between these two groups. Those who did not participate in Wave 4 were somewhat more likely to be younger, male, Hispanic, undocumented, have lower levels of education, report never having had health insurance, or prefer taking the survey in Spanish. In order to further isolate the demographic factors associated with completing the Wave 4 survey or not, we conducted a logistic regression analysis. After controlling for demographic characteristics such as income, race/ethnicity, and party identification, the factors associated with completing Wave 4 include being interviewed on a landline telephone, being older, having a disability, and having higher levels of education. The factors associated with not completing Wave 4 are being male and being Hispanic as well as being undocumented. This pattern is similar when looking at those who completed all 4 waves as well as those who have not participated since taking the initial baseline survey. As noted above, weighting corrects for some of these differences.

Methodology

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