Elyse O. Kharbanda

Effect of a Text Messaging Intervention on Influenza Vaccination in an Urban, Low-Income Pediatric and Adolescent Population: A Randomized Controlled Trial

CONTEXT Influenza infection results in substantial costs, morbidity, and mortality. Vaccination against influenza is particularly important in children and adolescents who are a significant source of transmission to other high-risk populations, yet pediatric and adolescent vaccine coverage remains low. Traditional vaccine reminders have had a limited effect on low-income populations; however, text messaging is a novel, scalable approach to promote influenza vaccination. OBJECTIVE To evaluate targeted text message reminders for low-income, urban parents to promote receipt of influenza vaccination among children and adolescents. DESIGN, SETTING, AND PARTICIPANTS Randomized controlled trial of 9213 children and adolescents aged 6 months to 18 years receiving care at 4 community-based clinics in the United States during the 2010-2011 influenza season. Of the 9213 children and adolescents, 7574 had not received influenza vaccine prior to the intervention start date and were included in the primary analysis. INTERVENTION Parents of children assigned to the intervention received up to 5 weekly immunization registry-linked text messages providing educational information and instructions regarding Saturday clinics. Both the intervention and usual care groups received the usual care, an automated telephone reminder, and access to informational flyers posted at the study sites. MAIN OUTCOME MEASURES Receipt of an influenza vaccine dose recorded in the immunization registry via an electronic health record by March 31, 2011. Receipt was secondarily assessed at an earlier fall review date prior to typical widespread influenza activity. RESULTS Study children and adolescents were primarily minority, 88% were publicly insured, and 58% were from Spanish-speaking families. As of March 31, 2011, a higher proportion of children and adolescents in the intervention group (43.6%; n = 1653) compared with the usual care group (39.9%; n = 1509) had received influenza vaccine (difference, 3.7% [95% CI, 1.5%-5.9%]; relative rate ratio [RRR], 1.09 [95% CI, 1.04-1.15]; P = .001). At the fall review date, 27.1% (n = 1026) of the intervention group compared with 22.8% (n = 864) of the usual care group had received influenza vaccine (difference, 4.3% [95% CI, 2.3%-6.3%]; RRR, 1.19 [95% CI, 1.10-1.28]; P < .001). CONCLUSIONS Among children and adolescents in a low-income, urban population, a text messaging intervention compared with usual care was associated with an increased rate of influenza vaccination. However, the overall influenza vaccination rate remained low. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01146912.

Text message reminders to promote human papillomavirus vaccination

OBJECTIVE To implement and evaluate text message reminders for the second (HPV2) and third (HPV3) vaccine doses. DESIGN Site-based intervention. SETTING Nine pediatric sites (5 academic and 4 private) located in New York City. PARTICIPANTS Parents of adolescents 9-20 years who received HPV1 or HPV2 during the intervention period, January-June 2009. INTERVENTION Parents who enrolled received up to three weekly text message reminders that their daughter was due for her next vaccine dose. OUTCOME MEASURE On-time receipt of the next vaccine dose, within one month of its due date. RESULTS During the intervention period, of 765 eligible HPV vaccine events, 434 enrollment instructions were distributed to parents (56.7% of doses). Parents of 124 adolescent girls (28.6% of those handed instructions) activated text message reminders. Comparing children of parents who enrolled versus those who did not, on-time receipt of next HPV vaccine dose occurred among 51.6% (95% CI 42.8-60.4%) versus 35.0% (95% CI 29.6-40.2%) of adolescents (p=.001). Similarly, among a historical cohort of adolescents, receiving HPV1 or HPV2 in the six months prior to the intervention period, on-time receipt of next vaccine dose was noted for 38.1% (95% CI 35.2-41.0%) (p=.003). Increases in receipt of next vaccine dose among intervention subjects were sustained at 4 months following the vaccine due date. Using a logistic regression model, after controlling for insurance and site of care, intervention subjects were significantly more likely than either control population to receive their next HPV vaccine dose on-time. CONCLUSION Among those choosing to enroll, text message reminders were an effective intervention to increase on-time receipt of HPV2 or HPV3.

Text4Health: a qualitative evaluation of parental readiness for text message immunization reminders.

We conducted focus groups and individual interviews in a diverse population of parents to qualitatively explore preferences and readiness for text message immunization reminders. We used content analysis to review and independently code transcripts. Text message reminders were well-accepted by parents; many thought they would be more effective than standard phone or mail reminders. Parents preferred text message reminders to be brief and personalized. Most parents were able to retrieve sample text messages but many had difficulty with interactive texting.

Prehypertension and Hypertension in Community-Based Pediatric Practice

OBJECTIVE: To examine the prevalence of prehypertension and hypertension among children receiving well-child care in community-based practices. METHODS: Children aged 3 to 17 years with measurements of height, weight, and blood pressure (BP) obtained at an initial (index) well-child visit between July 2007 and December 2009 were included in this retrospective cohort study across 3 large, integrated health care delivery systems. Index BP classification was based on the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents: normal BP, <90th percentile; prehypertension, 90th to 94th percentile; hypertension, 3 BP measurements ≥95th percentile (index and 2 subsequent consecutive visits). RESULTS: The cohort included 199 513 children (24.3% aged 3–5 years, 34.5% aged 6–11 years, and 41.2% aged 12–17 years) with substantial racial/ethnic diversity (35.9% white, 7.8% black, 17.6% Hispanic, 11.7% Asian/Pacific Islander, and 27.0% other/unknown race). At the index visit, 81.9% of participants were normotensive, 12.7% had prehypertension, and 5.4% had a BP in the hypertension range (≥95th percentile). Of the 10 848 children with an index hypertensive BP level, 3.8% of those with a follow-up BP measurement had confirmed hypertension (estimated 0.3% prevalence). Increasing age and BMI were significantly associated with prehypertension and confirmed hypertension (P < .001 for trend). Among racial/ethnic groups, blacks and Asians had the highest prevalence of hypertension. CONCLUSIONS: The prevalence of hypertension in this community-based study is lower than previously reported from school-based studies. With the size and diversity of this cohort, these results suggest the prevalence of hypertension in children may actually be lower than previously reported.

Influenza Vaccine Text Message Reminders for Urban, Low-Income Pregnant Women: A Randomized Controlled Trial

OBJECTIVES We evaluated the impact of influenza vaccine text message reminders in a low-income obstetric population. METHODS We conducted a randomized controlled trial that enrolled 1187 obstetric patients from 5 community-based clinics in New York City. The intervention group received 5 weekly text messages regarding influenza vaccination starting mid-September 2011 and 2 text message appointment reminders. Both groups received standard automated telephone appointment reminders. The prespecified endpoints were receipt of either pre- or postpartum influenza vaccination calculated cumulatively at the end of each month (September-December 2011). RESULTS After adjusting for gestational age and number of clinic visits, women who received the intervention were 30% more likely to be vaccinated as of December 2011 (adjusted odds ratio [AOR] = 1.30; 95% confidence interval [CI] = 1.003, 1.69 end of September: AOR = 1.34; 95% CI = 0.98, 1.85; October: AOR = 1.35; 95% CI = 1.05, 1.75; November: AOR = 1.27; 95% CI = 0.98, 1.65). The subgroup of women early in the third trimester at randomization showed the greatest intervention effect (December 31: 61.9% intervention vs 49.0% control; AOR = 1.88; 95% CI = 1.12, 3.15). CONCLUSIONS In this low-income obstetric population, text messaging was associated with increased influenza vaccination, especially in those who received messages early in their third trimester.

Maternal influenza vaccine and risks for preterm or small for gestational age birth.

OBJECTIVE To study the impact of influenza vaccine administered to pregnant women during all trimesters on the rates of preterm and small for gestational age (SGA) births, evaluating both increased and decreased risk. STUDY DESIGN This retrospective observational matched cohort study involved 7 Vaccine Safety Datalink sites across the US for the 2004-05 through 2008-09 influenza seasons. Cohort eligibility and outcomes were determined from administrative, claims, medical records, and birth data. In propensity score- and vaccine exposure time-matched analyses, ORs for preterm and SGA births were calculated. RESULTS Among 57 554 matched vaccinated and unvaccinated pregnant women, including 16 240 women in the first trimester, maternal vaccination was not associated with increased or decreased risk for preterm birth (OR for delivery at <37 weeks gestation, 0.97 [95% CI, 0.93-1.02]; for delivery at ≤32 weeks gestation, 0.98 [95% CI, 0.86-1.12]; and for delivery at ≤34 weeks gestation, 0.96 [95% CI, 0.88-1.04]) or SGA birth (OR for <5th percentile weight for gestational age, 1.02 [95% CI, 0.96-1.09], and for <10th percentile weight for gestational age, 1.00 [95% CI, 0.96-1.04]). Similarly, first trimester vaccination was not associated with increased or decreased risk for preterm or SGA birth. CONCLUSION Receipt of trivalent inactivated influenza vaccine during pregnancy was not associated with increased or decreased risk of preterm or SGA birth. These findings support the safety of vaccinating pregnant women against influenza during the first, second, and third trimesters, and suggest that a nonspecific protective effect of the influenza vaccine for these outcomes does not exist.

Maternal safety of trivalent inactivated influenza vaccine in pregnant women

OBJECTIVE: To estimate the risks for medically attended events occurring within 42 days of receiving trivalent inactivated influenza vaccine and to evaluate specific risks of first-trimester vaccination. METHODS: This retrospective observational cohort study compared rates of medically attended adverse events in trivalent inactivated influenza-vaccinated and unvaccinated pregnant women in the Vaccine Safety Datalink. Using a Poisson distribution and log link, we calculated maternal adjusted incident rate ratios for composite safety outcomes for the full cohort and the subset vaccinated during the first trimester. RESULTS: The cohort included 75,906 vaccinated (28.4% in the first trimester) and 147,992 unvaccinated women matched by age, site, and pregnancy start date. In the first 3 days after vaccination, trivalent inactivated influenza vaccine was not associated with increased risk of specified medically attended events, including allergic reactions, cellulitis, and seizures (full cohort adjusted incident rate ratio 1.12, 95% confidence interval [CI] 0.81–1.55; P=.48; first-trimester adjusted incident rate ratio .97, 95% CI 0.53–1.78; P=.93). In the first 42 days, no incident cases of Guillain-Barré syndrome, optic neuritis, transverse myelitis, or Bells palsy were identified. Trivalent inactivated influenza vaccine was not associated with thrombocytopenia (full cohort adjusted incident rate ratio 0.90, 95% CI 0.68--1.19; P=.45; first-trimester adjusted incident rate ratio 0.56, 95% CI 0.22–1.39; P=.21) or an acute neurologic event (full cohort adjusted incident rate ratio 0.92, 95% CI 0.54–1.6; P=.75; first-trimester adjusted incident rate ratio 1.05, 95% CI 0.46–2.38; P=.91). CONCLUSIONS: Receipt of trivalent inactivated influenza vaccine during pregnancy was not associated with increased risk of adverse events in the 42 days after vaccination, supporting its safety for the mother. LEVEL OF EVIDENCE: II

Inactivated influenza vaccine during pregnancy and risks for adverse obstetric events.

OBJECTIVE: To compare risks for adverse obstetric events between females who did and did not receive trivalent inactivated influenza vaccine during pregnancy. METHOD: This retrospective, observational cohort study was conducted at seven Vaccine Safety Datalink sites. Pregnancies were identified from administrative and claims data using a validated algorithm. Females vaccinated while pregnant from 2002 to 2009 were matched one-to-two with replacement to unvaccinated pregnant females. Using a generalized estimating equation method with a Poisson distribution and log link, we evaluated the association of trivalent inactivated influenza vaccine with 13 outcomes. Given our large sample size and multiple comparisons (19 contrasts), a cutoff for significance of P<.005 was selected a priori. RESULTS: Our cohort included 74,292 vaccinated females matched on age, site, and pregnancy start date with 144,597 unvaccinated females. We did not observe increased risks within 42 days of vaccination for hyperemesis, chronic hypertension, gestational hypertension, gestational diabetes, proteinuria, or urinary tract infection. Using a risk window from vaccination through pregnancy end, we did not observe increased risks after vaccination for proteinuria, urinary tract infection, gestational hypertension, preeclampsia or eclampsia, chorioamnionitis, puerperal infection, venous complications, pulmonary embolism, or peripartum cardiomyopathy. A reduced risk for gestational diabetes after vaccination was detected (adjusted hazard rate ratio 0.88, 95% confidence interval 0.83–0.93), likely as a result of healthy vaccine bias or earlier detection among vaccinees. CONCLUSION: In this large cohort, influenza vaccination during pregnancy was not associated with increased risks for medically attended adverse obstetric events. LEVEL OF EVIDENCE: II

Association of Tdap Vaccination With Acute Events and Adverse Birth Outcomes Among Pregnant Women With Prior Tetanus-Containing Immunizations

IMPORTANCE The Advisory Committee on Immunization Practices (ACIP) recommends the tetanus, diphtheria, and acellular pertussis (Tdap) vaccine for pregnant women during each pregnancy, regardless of prior immunization status. However, safety data on repeated Tdap vaccination in pregnancy is lacking. OBJECTIVE To determine whether receipt of Tdap vaccine during pregnancy administered in close intervals from prior tetanus-containing vaccinations is associated with acute adverse events in mothers and adverse birth outcomes in neonates. DESIGN, SETTING, AND PARTICIPANTS A retrospective cohort study in 29,155 pregnant women aged 14 through 49 years from January 1, 2007, through November 15, 2013, using data from 7 Vaccine Safety Datalink sites in California, Colorado, Minnesota, Oregon, Washington, and Wisconsin. EXPOSURES Women who received Tdap in pregnancy following a prior tetanus-containing vaccine less than 2 years before, 2 to 5 years before, and more than 5 years before. MAIN OUTCOMES AND MEASURES Acute adverse events (fever, allergy, and local reactions) and adverse birth outcomes (small for gestational age, preterm delivery, and low birth weight) were evaluated. Women who were vaccinated with Tdap in pregnancy and had a prior tetanus-containing vaccine more than 5 years before served as controls. RESULTS There were no statistically significant differences in rates of medically attended acute adverse events or adverse birth outcomes related to timing since prior tetanus-containing vaccination. [table: see text]. CONCLUSIONS AND RELEVANCE Among women who received Tdap vaccination during pregnancy, there was no increased risk of acute adverse events or adverse birth outcomes for those who had been previously vaccinated less than 2 years before or 2 to 5 years before compared with those who had been vaccinated more than 5 years before. These findings suggest that relatively recent receipt of a prior tetanus-containing vaccination does not increase risk after Tdap vaccination in pregnancy.

Maternal Tdap vaccination: Coverage and acute safety outcomes in the vaccine safety datalink, 2007-2013.

INTRODUCTION Since October 2012, the combined tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccine (Tdap) has been recommended in the United States during every pregnancy. METHODS In this observational study from the Vaccine Safety Datalink, we describe receipt of Tdap during pregnancy among insured women with live births across seven health systems. Using a retrospective matched cohort, we evaluated risks for selected medically attended adverse events in pregnant women, occurring within 42 days of vaccination. Using a generalized estimating equation, we calculated adjusted incident rate ratios (AIRR). RESULTS Our vaccine coverage cohort included 438,487 live births between January 1, 2007 and November 15, 2013. Across the coverage cohort, 14% received Tdap during pregnancy. By 2013, Tdap was administered during pregnancy in 41.7% of live births, primarily in the 3rd trimester. Our vaccine safety cohort included 53,885 vaccinated and 109,253 matched unvaccinated pregnant women. There was no increased risk for a composite outcome of medically attended acute adverse events within 3 days of vaccination. Similarly, across the safety cohort, over a 42 day window, incident neurologic events, thrombotic events, and new onset proteinuria did not differ by maternal receipt of Tdap. Among women receiving Tdap at 20 weeks gestation or later, as compared to their matched controls, there was no increased risk for gestational diabetes or cardiac events while venous thromboembolic events and thrombocytopenia were diagnosed within 42 days of vaccination at slightly decreased rates. CONCLUSION Tdap coverage during pregnancy increased from 2007 through 2013, but was still below 50%. No acute maternal safety signals were detected in this large cohort.