This document summarizes a study that used text messaging to improve compliance for fasting requirements for oral glucose tolerance tests and calling in for sexually transmitted disease results among NHANES survey respondents. The study found that text message reminders significantly improved compliance rates compared to previous years when only letters and phone calls were used. Compliance was highest among respondents who received text messages compared to those who did not have cell phones or did not consent to texting. The study demonstrated that text messaging is an effective and low-cost strategy to increase response rates for health surveys.

1. Text Messaging to Improve Respondent
Fasting and STD Results Compliance
Lew Berman, PhD, MS
Division of Health and Nutrition Examination Surveys
National Center for Health Statistics
Centers for Disease Control and Prevention
May 22, 2012

2. Presentation Outline
• NHANES Background
• Compliance problems
• Text Messaging Objective
• Solution
• Protocol and Results
• Discussion and Limitations
• Conclusion
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3. National Health and Nutrition
Examination Survey
• Assess the health of the US population each year
• N = 5000 / year
• 15 PSUs
• Nationally representative
• All ages
• HH questionnaire
• Extensive physical examination, specimen
collection, and follow-up exams / questionnaires
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4. Topics
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5. Oral Glucose Tolerance
• Goal: to reassess the prevalence of diabetes and
impaired glucose tolerance in the US population
ages 12 and older.
• Protocol
– Fasting blood glucose test
– Drink sweet liquid
– Blood glucose test
• Problem: reminder letters and phone calls not
consistently reinforcing fasting instructions
(compliance).
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6. NHANES Respondent 9-Hour OGTT
Fasting Compliance, 1999-2009
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70
80
90
100
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
%
Year
fasting compliance

7. Sexually Transmitted Disease (STD)
Results
• Goal: to ensure that respondents call in for their STD
results. Eligible respondents are 14-59 years old.
• Protocol
– Specimen collection at MEC
– Respondent provides password at MEC to receive results
– Laboratory processing for chlamydia, genital herpes, HIV,
female human papillomavirus
– Respondent calls NCHS physician and provides password
for results
• Problem: decline in proportion of respondents who
call-in for results (compliance)
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8. NHANES Respondent STD Call-in
Compliance 1999-2008
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50
60
70
80
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
%
Year
STD Results Compliance

9. Text Messaging Objective
Contact respondents with text message
reminders to increase OGTT fasting
compliance and STD call-in compliance.
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10. Obtaining Permission to Text
• Permission requested during home interview
• Age
– 12-15 year olds: parents respond
– 16+: answer for themselves
• Describe messages to be received
• Obtain respondent cell phone number
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11. Text Message Solution
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Text
Messaging
Application
Short
Message
Peer-2-Peer
Gateway
Cellular
Carriers
Phone #,
text message

12. Example OGTT
Fasting Text Messaging Protocol
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MEC Exam &
Specimen
Collection
Home
Screener and
Interview
June 1 June 28
1pm on
June 27
7pm on
June 27
Text Message: “Your health exam is at 8:30am tomorrow. Please do not
eat or drink anything except water after 11:30am tonight.”

13. OGTT Text Messaging Results
May 2011 – May 2012
Eligible and
Blood Drawn
(1636)
No Cell phone
(567)
No Fast (49)
Fast (518,
91.4%)
Cell Phone
(1069)
No Permission
to Contact
(403)
No Fast (35)
Fast (368,
91.3%)
Permission To
Contact (666)
No Text (178)
No Fast (8)
Fast (170,
95.5%)
Text (488)
No Fast (14)
Fast (474,
97.1%)
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14. Example
STD Text Messaging Protocol
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MEC Exam &
Specimen
Collection
Home
Screener and
Interview
+38d +48d +58d
+38d +48d +58d
Text Message: “Reminder: please call 888-301-2360 to get your
password protected test results from the health survey.”
18 - 59
year olds
14 – 17
year olds
June 1 June 15
July 23
August
2
August
12

15. STD Text Messaging Results
May 2011 – May 2012
Eligible and
Blood Drawn
(2243)
No Cell phone
(548)
No Call-in
(253)
Call-in
(295,
53.8%)
Cell Phone
(1695)
No Permission
to Contact
(527)
No Call-in
(229)
Call-in
(298,
56.5%)
Permission To
Contact (1168)
No Text (337)
No Call-in
(114)
Call-in
(223,
66.2%)
Text (831)
No Call-in
(337)
Call-in
(494, 60%)
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16. Limitations
• Not an experimental design
• Text messaging added to existing protocol
• STD call-ins not parsed by age group and
differing protocol
• Some text messages not received for unknown
reasons
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17. Conclusion
• Text messaging is easy to implement and cost effective
• OGTT
– Cell-phone users have greater compliance than non-cell
phone users
– Compliance with text messaging higher than 1999-2009
• STD
– Cell-phone users have greater compliance than non-cell
phone users
– Compliance improved with text messaging, but not as high
as 1999-2003.
• Plans underway to include text messaging for other
parts of NHANES
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18. Acknowledgements
• Steve Bernas, Westat
• Tatiana Nwankwo, CDC/NCHS
• Kathryn Porter, CDC / NCHS
5/21/2012 18

19. Percent of NHANES Respondents Participating in Oral
Glucose Tolerance Test Morning Session with a Cell
Phone by Age and Race, May 2011-May 2012
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0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
12-19 20-39 40-59 60+
%
Age Group
Hispanic
Black
Asian
White/Other

20. Percent of NHANES Respondents Participating in STD
Testing with a Cell Phone by Age and Race, May 2011-
May 2012
5/21/2012 21
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
14-17 18-59
%
Age Group
Hispanic
Black
Asian
White/Other