Text4Health: Immunization-Registry-Linked Text Message Reminders Improve Adolescent Immunization Coverage Melissa Stockwell, MD, MPH Elyse Olshen Kharbanda, MD, MPH, Raquel Andres, PHD, Marc Lara, MBA, David Vawdrey, PhD, Karthik Natatajan, MS Vaughn Rickert, PsyD 42nd National Immunization Conference Atlanta, GA April 21, 2010  Funded by HRSA Maternal Child Health Bureau grant R40MC08961

Adolescent Immunization Schedule In the past few years, three new vaccines have been added to the routine adolescent immunization schedule. These vaccines – Tdap, HPV and MCV4 – have the potential to greatly improve the health of our community. In order for these vaccines to have their greatest impact, uptake must be high. As some of you know, the yellow denotes when they vaccines are recommended – at the 11-12 year visit, while the green denotes when these and other vaccines may be given to adolescents as “catch-up” vaccines Coverage rates ofr tdap and mCva re around 40%, lower than for early childhood

Reminder-recalls Recommended by: AAP, SAM, AAFP, ACIP, NVAC Meta-analysis by US Task Force on Community Preventive Services found median increase of 8% (range, −7%–31%) More recent meta-analysis found reminder- recalls childhood vaccinations OR=1.47 (95% CI 1.28-1.68) Traditional reminder-recalls in adolescents and underserved populations have not been very successful Briss et al 2000; Szilagyi and Jacobson 2005.

Why cellular technology is ideal Over 91% US adults use cell phones Use may be higher in underserved populations Stability of cell phone #s Provide cues to action Use with immunization registry Wireless Quick Facts June 2009, CTIA, The Wireless Association. Available at http://www.ctia.org/media/index.cfm/AID/10323; Accessed April 5, 2010. Blumberg et al 2006, Castano et al 2006 Immunization reminder-recalls have been well evaluated and shown to be effective in increasing immunization coverage. They are recommended by a variety of groups including theus task force on preventive services, aap and sam. So why have we decided to focus on text messaging immunization reminders? A few reasons – first we know that traditional reminder-recalls – through phone calls or letters in the mail can be challenging in low income populations due to unstable home phone number, delayed receipt of mail and expense; cellular technology may be ideal as cell phones are in widespread use – 76%... And cell numbers may actually be higher and numbers more stable than land line use; text message reminder recalls will work by providing cues to action – this is from the health belief model – one model describing immunization seeking behaviors

Study Objectives Primary: Secondary: To evaluate the impact of registry-linked text messages on receipt of immunizations among adolescents in a low-income, urban community. Secondary: To estimate the incremental cost-effectiveness ratio for this intervention.

Study Setting and Design Academic medical center in underserved community Primarily Latino, Medicaid/SCHIP Hospital and network of affiliated ambulatory clinics (n=6) Randomized at practice level 2 intervention, 4 control Pre-intervention immunization rates (child and adolescent), size of adolescent population Part of same practice network, minority, publicly insured Used EzVAC to automatically identify eligible adolescents Adol population and baseline rates

Study Population Eligible parents Child 11-18 years old Child visited one of 6 clinical sites in the past year Cell phone number in hospital registration system Child needed MCV4 and/or Tdap Tdap: not having received Tdap, not received Td in last 2 years

Study Design Weekly: random sample adolescents in need of Tdap/MCV, matched with control (age, gender) Identified in EzVAC immunization registry Point-of-service registry, linked to hospital billing system All children receiving care at hospital and affiliated ambulatory clinic Used EzVAC to automatically identify eligible adolescents Adol population and baseline rates

Intervention Automated immunization text reminders Initial message at randomization Additional at weeks 1, 2, 6 and 7 Texts designed based on focus group input Child’s name, clinic name, clinic phone number, walk in times Spanish and English texts Sent in language listed in registration system 1st message allowed switch to Spanish Option to stop Kharbanda EO, Stockwell MS, Fox HW, Rickert VI. Text4Health: a qualitative evaluation of parental readiness for text message immunization reminders. Am J Public Health. Dec 2009;99(12):2176-2178.

Sample text message Chris is due for shots. Come to Audubon clinic Mon-Thu 9-11am, Fri 1-3:30pm. To stop reminders text QUIT. Para espanol text ESPANOL

Main Outcome Measures Primary outcome: Secondary outcome: Receipt of needed adolescent vaccine (MCV4 or Tdap) at 4, 12 and 24 weeks after receipt first message Secondary outcome: Receipt of any additional needed immunization

Analysis Chi square: differences in receipt of vaccine, intervention vs control Nested ANOVA (Analysis of variance): account for effect of variance between sites Multivariate logistic regression: impact of age, gender, race/ethnicity, insurance status and language on the intervention effects Generalized linear models

Incremental Cost Effectiveness Costs and benefits compared to standard of care (no reminder-recalls) Outcomes: cost per additional patient immunized cost per additional vaccine Extrapolated to continue intervention for a two-year period in two populations: A. All teens in hospital-based registry B. Hypothetical population of 100,000 teens Variable costs: personnel time to monitor messaging platform Discounting not applied A next step was to determine the incremental cost effectiveness of our text messaging intervention. In these analyses, we compared the costs and benefits of our intervention versus standard of care, which was no reminder-recalls. Our outcomes were cost per additional patient immunized and cost per additional vaccine; we then extrapolated findings from our study to continue the intervention over a two year period in 2 populations – all teens in our hospital based registry and a hypothetical population of 100,000 teens included in a population-based registry; as costs and benefits were occurring close togeether, discounting was not applied

Characteristics of Study Population Intervention (ITT) Control (N = 195) (N= 166) Age (mean +/-SD, yrs) 16.3 +/- 1.7 16.1 +/- 1.7 Gender %, (n) Male 39.5 (77) 45.2 (75) Female 60.5 (118) 54.8 (91) Race/Ethnicity* %, (n) Black, non Latino 16.7 (32) 14.0 (21) Latino 52.6 (101) 58.0 (87) White, non Latino 2.6 (5) 4.0 (6) Other 28.1 (54) 24.0 (36) Insurance %, (n) Uninsured 11.8 (23) 10.9 (18) Medicaid 74.4 (145) 75.3 (125) SCHIP 4.1 (8) 7.2 (12) Private 9.7 (19) 6.6 (11) Primary Language %, (n) English 41.6 (81) 40.6 (67) Spanish 56.9 (111) 57.0 (94) Other 1.5 (3) 2.4 (4) No significant differences Note: No significant differences between intervention and control groups

Messages 821 text messages were sent 7 bounces, 5 wrong numbers (6.2%) 5 families opted out (2.7%) on the intervention effects Generalized linear models

* At 12 weeks: 12.3% point difference (CI 4.4%- 20.4%)

At 4 weeks: 11.8% point difference (CI 5.2%- 18.5%) Most common other vaccines administered included: Human papilloma virus, Hepatitis A, influenza, varicella, measles/mumps/rubella At 4 weeks: 11.8% point difference (CI 5.2%- 18.5%) At 12 weeks: 12.5% point difference (CI 3.6%- 21.4%) At 24 weeks: 12.5% point difference (CI 2.7%- 22.3%) Most common: HPV, Hepatitis A, influenza, varicella, MMR

Nested ANOVA Nested ANOVA did not find a significant contribution due to the sites at any time points for all analyses.

Multivariate Analyses Receipt of MCV and/or Tdap vaccine 4 weeks: AOR 4.12 (95% CI 1.72, 9.90) 12 weeks: AOR 2.40 (95% CI 1.34, 4.32) 24 weeks: AOR 2.48 (95% CI 1.48-4.15) * All analyses controlled for age, gender, race/ethnicity, insurance status and language

Incremental Cost Effectiveness For all teens in our hospital-based registry: Cost per adolescent immunized: $17.71 Cost per additional vaccine: $4.32 For a hypothetical cohort of 100,000 teens Cost per adolescent immunized: $1.71 Cost per additional vaccine: $.42 We found that the incremental cost effectiveness of our intervention, if continued over two years for all teens in our registry would be 17.71 per adolescent immunized and 4.32 per additional vaccine delivered In a hypothetical cohort of 100,000 teens we estimated that costs per adolescent immunized would be 1.71 while cost per additional vaccine delivered would be .42

Summary 11-18% increase (AOR 2.4-4.1) receipt MCV/Tdap Meta-analyses 8% median change,OR 1.7 Low-income urban children and adolescents Sustained effect, additional vaccines Economies of scale Briss et al 2000, Szilagyi and Jacobson et al 2005, Szilagyi et al. 2006, Irigoyen et al 2006, Hambidge et al 2004, Daley et al, 2002 Text messaging effective way to deliver immunization reminders to families, even in an underserved, adolescent population:

Limitations Incomplete records: 95% given at our sites Randomized within a site not overall: carry over bias, nested ANOVA Cell phone available: EHR, 53% our population Not population wide: limits of capacity Generalizability Simplified cost analyses, assumptions In addition, registry records may have been incomplete, and some adolescents texted may have really have not been due for vaccination; they may ave accounted for some number of patients who had visits but did not receive the needed shot Assumptions: sustained efficacy but likely those who did not get it after a few rounds will not get it Assume pop aging in is same number as who age out Could be other variable costs not aware of

Future Directions Dissemination to a larger immunization registry, department of health, or large group practice to improve immunization coverage Use of reminder recalls for other age groups, other vaccines (flu)

Acknowledgements Text4Health-Registry Clinical Sites New York Presbyterian Hospital Ambulatory Care Network Text4Health Study Team Elyse Olshen Kharbanda, MD MPH Harrison Fox, BA Vaughn I. Rickert, PsyD Raquel Andres Martinez, PhD Oscar Pena, JD Marcos Lara, MBA David Vawdrey, PhD Karthik Natarajan, MA Balendu Dasgupta, MA For more information visit: www.text4health.org This study is funded by HRSA R40MC08961-01-00