Physician Adoption of Adolescent Tdap Recommendations Mandy Dempsey, MD, PhD, MPH CHEAR Unit, Dept of Pediatrics University of Michigan NIC, 2008

Pertussis Pertussis is one of the only VPDs with an increasing incidence Adolescents at high risk of contracting illness and are a main reservoir of infection

Tdap Vaccines In 2005, two vaccines combing tetanus, diphtheria and acellular pertussis antigens were licensed ACIP recommended all adolescents ages 11-18 years receive Tdap instead of Td booster

Previous Study of Physician Attitudes 2005 survey of FP and PD to inform ACIP deliberations about Tdap Moderate support for replacing adolescent Td with Tdap FPs less enthusiastic about the vaccine that PDs Lack of adolescent visits identified as potential barrier to Tdap administration

Research Objectives Determine physician practices regarding uptake of adolescent Tdap recommendations Evaluate whether specialty-based disparities in attitudes and practices regarding Tdap still exist

Study Sample National random sample of 725 FP and 725 PD from AMA master file Exclusions >70 years old Residents Providing care at federal facilities (e.g. VA) No outpatient adolescent care Not in active practice

Study Design Mail-based survey 3 mailings – Jan-March, 2007 Utilization patterns, attitudes, barriers to stocking and administration, use with MCV4, acceptable intervals between Tdap and Td 3 mailings – Jan-March, 2007 $5 incentive

Analytic Methods Descriptive statistics Chi-squared analyses Multivariable logistic regression

Results – Response Rate 287 surveys excluded 702 returned – 60% 53% FP 68% PD Gender, age, medical degree, geographic area, yrs since graduation similar between NR and R

Respondent Characteristics All (n=702) FP (n=302) PD (n=400) Age <35 >50 8% 36% 9% 38% 7% 35% Yrs since graduation <10 >25 18% 28% 20% 24% 17% 31% Proportion adolescent patients* <10% 10-25% >25% 16% 70% 14% 27% 3% 69% 23% Previous experience w/adolescent pertussis* Never 1-5 times ≥6 times 33% 45% 22% 46% 41% 13% 48% 39% * Significant difference between medical specialties, p<.0001

Tdap Recommendation Patterns Frequency of Recommendation All Respondents (n=702) FP (n=302) PD (n=400) p-value 11-12 year old adolescents without previous Td booster Routinely 87% 75% 96% <.0001 Sometimes 7% 12% 3% Rarely/never 6% 13% 1% 13-18 year old adolescents without previous Td booster 89% 80% 10% 5%

Physician Characteristics Associated with Routinely Recommending Tdap, Bivariate p-value Professional Society membership No Yes 77% 90% .0003 Stock Tdap in the practice 44% 92% <.0001 Medical Specialty FP PD 75% 96% Previous diagnostic experience for adolescent pertussis Never 1-5 times ≥ 6 times 79% 89% 94% .0002 *11-12 year olds

Routinely Recommending Tdap Not associated with: Practice size Practice affiliation Number of outpatients/week % adolescent patients

Physician Characteristics Associated with Routinely Recommending Tdap, Multivariate OR 95% CI p-value Professional Society membership No Yes Ref 1.68 - 0.88-3.21 .1130 Stock Tdap in the practice 7.99 4.24-15.07 <.0001 Medical Specialty FP PD 4.83 2.51-9.27 Previous diagnostic experience for adolescent pertussis Never 1-5 times ≥ 6 times 1.19 2.00 0.67-2.12 0.82-4.89 .5598 .1285 *11-12 year olds

Tdap following Td Minimal Acceptable Time Interval All (n=702) FP (n=302) PD (n=400) At least 5 years 48% 57% 42% At least 2 years 44% 39% <2 years under special conditions 5% 2% 7% Don’t know 3% p =.0006

Co-administration with Menactra 90% of physicians* would co-administer Tdap with Menactra 95% PD vs. 81% FP (p<.0001) Of those that would not co-administer (n=61) 43% would wait 1 month between 30% would wait “no specific amount of time” * Among physicians that stocked Tdap in their practice

Stocking Tdap 90% of physicians stocked some form of Tdap 49% Adacel® 15% Boostrix® 15% Both 21% Unsure

Characteristics Associated with Stocking Tdap % Physician Practices Stocking Tdap p-value Medical Specialty FP PD 79% 98% <.0001 Professional Society Membership No Yes 75% 93% Previous diagnostic experience with adolescent pertussis Never 1-5 times ≥ 6 times 82% 95%

Characteristics Associated with Stocking Tdap, cont’d % Physician Practices Stocking Tdap p-value Practice size 1 physician 2-4 physicians 5-9 physicians ≥10 physicians 76% 88% 96% 95% <.0001 Practice Offers Public Stock of Vaccines in General No Yes 84%

Stocking Tdap Not associated with: Practice affiliation Number of outpatients/week % adolescent patients

Barriers to Administering* Tdap Major Barrier Minor Barrier Not at Barrier Lack of adolescent visits 33% 37% 30% Too busy/other priorities during visits 2% 18% 80% Tdap supply problems 12% 32% 56% Reimbursement/coverage 8% 25% 67% Record keeping/knowing who needs Tdap 4% 71% * Among physicians who stock Tdap in their practices

Barriers to Stocking Tdap among Non-stocking Physicians Low volume adolescent patients (41%) Increased cost of Tdap relative to Td (39%) Inadequate reimbursement (31%)

Conclusions ACIP recommendations for adolescent Tdap have been largely adopted by PD and FPs Most physicians routinely recommend Tdap to 11-12 year olds as well as older adolescents Specialty-based differences in vaccination practices persist

Conclusions, cont’d Stocking Tdap in the practice was an important predictor of routinely recommending Tdap Lack of adolescent visits persists as a perceived barrier to vaccination

Limitations Response bias Respondents may be inherently more interested in immunization issues

Implications Ongoing need to educate providers, particularly FPs, about the need for Tdap vaccination Education should include information on incorporation of Tdap with other adolescent vaccines, and acceptable intervals following Td Addressing practice-level barriers such as the ability to stock vaccine in the office may improve adolescent vaccination rates

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