Reflecting the Community: Demographic Variations in Landline and Cell-Only

Households for a Statewide Telephone Survey

Sarah Walsh, MPH, CHES, Foundation for a Healthy KentuckyJennifer Chubinski, MS, The Health Foundation of Greater CincinnatiMichelle Vargas, Institute for Policy Research, University of Cincinnati

Eric Rademacher, PhD, Institute for Policy Research, University of Cincinnati

Presenter Disclosures

The following personal financial relationships with commercial interests relevant to this presentation existed during the past 12 months:

NO RELATIONSHIPS TO DISCLOSE.

Kentucky Health Issues Poll (KHIP)

• Questions vary by year, but include:– Health status– Socioeconomic variables– Public opinion on health related topics

• KHIP gives policymakers and advocates valuable data for keeping health on the public agenda.

KHIP

KHIP Methodology

• Conducted annually, since 2008• Random Digit Dial Telephone survey (RDD)– Cell phone sampling started 2009

• Data collection done by the Institute for Policy Research (IPR) at the University of Cincinnati

• Analysis done by Foundation staff

KHIP sample over time

2008 1,632 landline interviewsJanuary 16-February 11, 2008

2009 1,464 landline; 205 cell-only interviewsOctober 8-November 6, 2009

2010 1,469 landline; 208 cell-only interviewsDecember 3-22 and 27-28, 2010

2011 ≈ 1,200 landline; ≈ 300 cell any interviews

September 27-present

Cell-only Households, 2009-2010

Blumberg SJ, Luke JV, Ganesh N, et al. Wireless substitution: State-level estimates from the National Health Interview Survey, January 2007-June 2010. National health statistics reports; no 39. Hyattsville, MD: National Center for Health Statistics. 2011. Available at http://www.cdc.gov/nchs/nhis.html

Why Cell?

• KY high cell-only state• Vulnerable populations and more likely cell

phone-only users important to our mission– Low-income– Minority– Young adults

• More reliable sample of population

UNWEIGHTED Results

2009 Unweighted Results

percent Males 34.0% 48.8% 35.8% 48%

Landline Only Cell Only

Combined Sample

Weighted Target

percent Black 5.3% 8.9% 5.8% 7%

percent 18-45 26.5% 71.7% 32.1% 56%

2010 Unweighted Results

percent Males 35.0% 45.7% 36.3% 48%

Landline Only Cell Only

Combined Sample

Weighted Target

percent Black 5.6% 8.2% 5.9% 7%

percent 18-45 22.7% 61.5% 27.5% 56%

Results (unweighted)

• Cell phone sample increased size (as compared to a landline only sample) of:– Minority (races not white, and Hispanic) ≈ 1%– **Young adults ≈3-4%– Men ≈2%– Low-income adults (under 100 and 200% FPG) ≈1%– Uninsured ≈2%

** strongest effect

WEIGHTED Results

2009 Results

Currently Uninsured 28.0% 27.5%

Weighted Landline Only

Weighted Combined Sample

Uninsured in Past Year 31.5% 31.7%

Below 100% FPL 27.1% 26.4%

Below 200% FPL 47.4% 47.3%

2010 Results

Currently Uninsured 21.3% 22.5%

Weighted Landline Only

Weighted Combined Sample

Uninsured in Past Year 29.8% 31.6%

Below 100% FPL 23.6% 24.7%

Below 200% FPL 48.1% 49.1%

Results (weighted)

• Most differences lost in weighting procedure– Weights based on 2008 American Community

Survey (ACS)– Sample weighted on age, race, sex, education,

regional distribution, number of adults and phone lines in the household.

• HOWEVER, the cell phone sample reduced the magnitude of the weights

Lessons Learned- KHIP 2011

• Cell sampling changed from cell only to cell mostly

• Larger percentage of cell phones• Larger cost with cell sampling, but cost is

going down– Previously 5x a landline response– Currently 3x a landline response

Draw your own conclusions

• Raw data available in free statistical portal– Online Analysis and Statistical Information System

(OASIS) www.oasisdataarchive.org

Draw your own conclusions

• Data available for mapping in free mapping portal- HealthLandscape www.healthlandscape.org

Questions?

Sarah WalshSenior Program Officer, Local Data for Local Action Initiative

(502) 326-2583swalsh@healthy-ky.org

Jennifer ChubinskiDirector of Community Research

(513) 458-6608jchubinski@healthfoundation.org