Materials and Methods
After institutional review broad approval at Partners Healthcare, we conducted a retrospective cohort study including all women delivering at our university hospital between Feb. 2013 and June 2013, following the implementation of the 2012 ACIP perinatal Tdap guidelines. Patients who were transferred to our hospital only for delivery were excluded from this cohort as their prenatal care records were not available electronically. Data on patient demographics, pregnancy outcomes, and vaccination status for both influenza and Tdap were abstracted from the longitudinal electronic medical record by 2 trained research personnel.
Univariate analysis was performed to describe the relationship between Tdap vaccination status and maternal age, marital status, race/ethnicity, parity, gestational age, prenatal care site, prenatal care provider type, insurance type, and influenza vaccination status. Multivariable logistic regression was performed to identify independent predictors of Tdap vaccination. Categorical data are presented as frequency counts (percent) and compared using a Yates corrected χ 2 or Fisher exact statistic as appropriate. Continuous variables are reported as means and medians where appropriate and compared using a 2-tailed, unpaired t test or Wilcoxon test when the data were not normally distributed. A P value of < .05 was considered statistically significant. SAS software version 9.1 (SAS Institute, Cary, NC) was used for statistical analysis.
Tdap vaccination program
The obstetrics department at the Massachusetts General Hospital is a large, faculty practice comprised of attending obstetricians, midwives, and perinatologists under a single leadership. We service a diverse patient population, 30% of whom receive public insurance, at the main hospital campus, as well as 4 neighborhood health centers. Following the ACIP Tdap guidelines issued in Oct. 2012, we focused on the education of staff and patients, as well as work flow modifications to vaccinate every pregnant woman. Materials were widely distributed to physicians, midwives, nurses, and medical assistants in the form of e-mails, faculty meetings, and in-service presentations given by both our department leadership and trained Tdap vaccine champions at every level.
In addition to educating the staff, consistent and uniform information was provided to the patients at the 26-28 week prenatal visit. Posters were placed throughout the waiting rooms and clinical offices. Physicians, nurses, and medical assistants were trained to answer questions about Tdap vaccination during pregnancy according to the American College of Obstetricians and Gynecologists “Frequently Asked Questions for Patients Concerning Tdap Vaccination.”
Tdap vaccine administered during pregnancy is universally covered by all private insurance carriers in Massachusetts as well as by the state subsidized healthcare program (MassHealth, Boston, MA). All patients were made aware that Tdap would be administered without a fee. To optimize our work flow, standing orders were put into place for Tdap vaccine administration by our nursing colleagues. Finally, vaccines were available at every clinical encounter and both physicians we well as nurses administered the injections during busy clinical sessions.
Results
1467 women delivered at our institution between February 2013 and June 2013. Our patients were, on average, 32 years old, 51% nulliparous, and ethnically diverse: White (59%), Hispanic (20.3%), Asian (11%), and Black (7.7%) ( Table 1 ). There were 1194 (81.6%) women who received the Tdap vaccine during the pregnancy. Of these 1194, 1101 (92%) received Tdap vaccination at or beyond 37 weeks’ gestation, whereas only 7% received the vaccine between 27 and 36 weeks. Less than 1% of patients who were vaccinated during pregnancy received the vaccine before 27 weeks.
| Demographic | n (%) |
|---|---|
| Mean age a | 32 (± 5.5) |
| Nulliparous | 756 (51.5) |
| Race/Ethnicity: | |
| White | 855 (59) |
| Black | 111 (7.7) |
| Asian | 161 (11) |
| Hispanic | 294 (20.3) |
| Ethnicity, other | 31 (2) |
| Married | 1064 (73) |
| Private insurance | 1010 (69) |
| Prenatal care at main campus | 1087 (74) |
| Prenatal provider MD | 1125 (76.7) |
| Gestational age | |
| <27 wks | 25 (1.7) |
| 27-36 6/7 wks | 125 (8.5) |
| ≥37 wks | 1313 (89.8) |
| Influenza vaccinated | 1150 (78.8) |
| Tdap vaccinated b | 1194 (81.6) |
| Total cohort c | 1467 |
a Data presented as Mean (± standard deviation)
b Tdap administered antenatally = 1096
c Numbers may not add to sample size secondary to missing data.
In univariate analysis, influenza vaccination during the pregnancy was a positive predictor of Tdap vaccination, whereas nulliparity, black race, and prematurity were noted to be negative predictors ( Table 2 ). After adjusting for potential confounders, 3 factors remained independent predictors of receiving the Tdap vaccine. Patients were more likely to receive Tdap if they had been vaccinated against influenza during this pregnancy (adjusted odds ratio [aOR], 1.7; 95% confidence interval [CI], 1.4–2.3). Black women were 60% less likely to receive the Tdap vaccine when compared with other women in the cohort (aOR, 0.42, 95% CI, 0.27–0.67). Also, women who delivered preterm were significantly less likely to receive the Tdap vaccine (aOR, 0.33, 95% CI, 0.22–0.48) ( Table 3 ). Although 21 (27%) of the preterm deliveries occurred before the recommended target for vaccination, 36 (63%) of the patients who delivered prematurely were between 27 and 37 weeks of gestation and would have been potentially eligible for the vaccine.
| Characteristic | Tdap vaccination n (%) | No Tdap vaccination n (%) | P value |
|---|---|---|---|
| Maternal age, y a | 32.3 (± 5.3) | 32.9 (± 6.2) | .12 |
| Nulliparity, n (%) | 598 (50.1) | 157 (58.4) | .01 |
| Race/Ethnicity, n (%) | < .01 | ||
| White | 700 (59.2) | 152 (57.1) | |
| Black | 74 (6.3) | 37 (13.9) | |
| Asian | 131 (11.1) | 30 (11.3) | |
| Hispanic | 251 (21.2) | 42 (15.8) | |
| Other | 26 (2.2) | 5 (1.9) | |
| Married, n (%) | 871 (73.3) | 190 (71.4) | .53 |
| Private insurance, n (%) | 822 (68.6) | 185 (69.0) | .95 |
| Prenatal care at MGH, n (%) | 885 (74.1) | 201 (64.7) | .84 |
| Prenatal provider MD, n (%) | 909 (76.1) | 212 (78.8) | .35 |
| Gestational age at delivery, wks b | 39.4 (38.4–40.4) | 39.3 (37.4–40.4) | < .01 |
| Preterm delivery, n (%) | 93 (7.8) | 57 (21.2) | < .01 |
| Influenza vaccination, n (%) | 972 (81.4) | 189 (70.3) | < .01 |
a Mean (± standard deviation) presented for normally distributed categorical data
b Median (25–75% interquartile range) presented for nonnormally distributed data.
| Predictor | Unadjusted OR (95% CI) | Adjusted OR (95% CI) a |
|---|---|---|
| Race: Black | 0.41 (0.27–0.63) | 0.42 (0.27–0.67) |
| Preterm delivery | 0.31 (0.22–0.45) | 0.33 (0.22–0.48) |
| Flu vaccine | 1.9 (1.41–2.57) | 1.7 (1.24–2.34) |
| Nulliparity | 0.72 (0.55–0.94) | 0.87 (0.57–1.32) |
a Adjusted for listed variables as well as maternal age, marital status, prenatal provider type and site, and insurance type–all of which were not significant predictors.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
