Missed Opportunities to Immunize Psychosocial and Practice Correlates Radmila Prislin, PhD, Mark H. Sawyer, MD, Michelle De Guire, MPH, MSW, Jesse Brennan, MS, Kathy Holcomb, MA, Philip R. Nader, MD Background: The goal of this pilot study was to correlate missed opportunities to immunize young children with providers’ psychosocial characteristics and self-reported immunization practices. Methods:
In a population of children aged 0 to 36 months, missed opportunities to immunize were established for a sample of 28 providers, who also responded to a valid and reliable instrument measuring the aforementioned variables.
Results:
Missed opportunities were significantly lower among providers with higher vested interest (r⫽⫺0.45, p⫽0.02) and tended to be lower among providers with more positive attitudes toward having all children properly immunized at every healthcare visit (r⫽⫺0.33, p⫽0.09). Neither knowledge nor perceived barriers correlated significantly with missed opportunities. Providers missed opportunities to immunize in over half of the visits studied (mean, 0.58), yet all of them reported always immunizing at preventive and follow-up visits, almost all (96.3%) at chronic illness visits, and a majority (78.6%) at acute care visits. As a result, none of the self-reported immunization practices was significantly correlated with missed opportunities.
Conclusions: Missed opportunities appear to be best predicted by motivational psychosocial factors and not by knowledge or perceived barriers. Self-reported immunization practices do not correspond to actual immunization behavior. Medical Subject Headings (MeSH): attitude, immunization, self-assessment (psychology), professional practice (Am J Prev Med 2002;22(3):165–169) © 2002 American Journal of Preventive Medicine
Introduction
I
mmunization is the most efficient and cost-effective method for preventing common childhood diseases, yet optimal immunization of preschool children appears to be an elusive goal.1,2 Among many factors contributing to the problem, failure to immunize children during office visits is likely the largest factor.3–7 Every healthcare visit during which a child eligible for immunization and without contraindication does not receive the needed vaccination is considered a missed opportunity.8 It is estimated that missed opportunities occur at 20% to 84% of child healthcare visits9 –12 in virtually all primary care settings.6,13 It is further estimated that elimination of missed opportunities would reduce the total undervaccination time
From the Department of Psychology, San Diego State University (Prislin), San Diego; and Division of Community Pediatrics, Partnership of Immunization Providers, University of California, San Diego (Sawyer, De Guire, Brennan, Holcomb, Nader), La Jolla, California Address correspondence and reprint requests to: Radmila Prislin, PhD, Department of Psychology, San Diego State University, San Diego, CA 92182-4611. E-mail:
[email protected].
(the number of months during which children are undervaccinated) by 50%12 and would improve coverage rates by up to 30%.14 Because of such a strong association between missed opportunities and undervaccination, it is important to examine factors leading to missed opportunities. Previous research has focused predominantly on factors associated with immunization practice policies. This research has documented that policies not to immunize during acute care visits14 –21 and not to administer multiple injections14,16,22–24 are strongly associated with high rates of missed opportunities. Studies of providerand system-associated factors, although fewer in number, have shown that providers’ incorrect interpretations of immunization contraindications14,23–25 and such system barriers as immunization costs and lack of personnel14,26 are predictive of high missed opportunity rates. Finally, there are indications that some family20 and child16 characteristics are also associated with missed opportunities. It is possible, however, that the effect of child characteristics (e.g., age) may actually reflect immunization policies not to administer multiple injections, supporting the contention that
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Table 1. Psychosocial variables: means, standard deviations, and correlations with missed opportunities Psychosocial variable
Mean
Standard deviation
Correlation (r)
p value
Knowledge (range: 0–14) Attitudes (range: 0–4) Vested interest (range: 0–4) Perceived barriers (range: 0–4) Self-efficacy (range: 0–4)
8.79 3.79 3.50 1.83 3.19
0.59 0.43 0.55 0.70 0.87
0.13 ⫺0.33 ⫺0.45 ⫺0.07 ⫺0.18
0.50 0.09 0.02 0.71 0.37
missed opportunities are determined primarily by factors under the control of providers.20 If interventions aimed at reducing missed opportunities by targeting providers are to be successful, it is important that they address provider-related characteristics associated with missed opportunities. Previous research indicates that knowledge about contraindications is such a characteristic (see above). The theory of planned behavior27 suggests that additional psychosocial variables, including attitudes and perceived control over immunizations, may also be significant determinants of missed opportunities. Attitudes indicate motivation and perceived control indicates perceived selfefficacy in following optimal immunization practices. This pilot study was undertaken as a first step toward establishing the extent to which knowledge, motivational factors, and perceived control factors are associated with missed opportunities. Motivational factors examined in this study include attitudes and vested interest; perceived control factors were self-efficacy and perceived seriousness of barriers to immunization.28 An additional and equally important goal of this study was to determine the extent to which providers’ perceptions of their immunization practice policies are related to missed opportunities. Accurate perception, as indicated by a strong correlation with missed opportunities, is a prerequisite for changing inadequate practices and for maintaining adequate practices. Moreover, in numerous studies, perceptions are used as a proxy for actual practices. Thus, it is relevant to establish the strength of association between perceptions and actual behavior. This study was undertaken as part of the Partnership of Immunization Providers (PIP) project. The PIP is collaborative public/private project created by the University of California, San Diego (UCSD) School of Medicine, Division of Community Pediatrics, in association with community clinics and small, private provider practices. Using multifaceted strategies, the PIP seeks to improve delivery of immunizations among preschool children in San Diego County, especially among those living in areas known to have lower-thanaverage immunization rates and designated as medically underserved by the healthcare community. Because PIP strategies target provider practice with an emphasis on reducing missed opportunities, it was 166
necessary to determine factors initially related to missed opportunities.
Methods Subjects Subjects in this pilot study were 28 providers from 10 urban clinics. These clinics were representative of those serving largely Medicaid-eligible populations and located in areas considered by the Health Resources and Service Administration to be “health professional shortage areas.”29 Six of the clinics were large community healthcare centers, and four were private practices. The total number of providers in the clinics varied from 3 to 14. Only providers who had at least 10 visits at which a child was eligible for immunization during the study period were included; thus, providers who saw children infrequently were excluded. This study received approval by the UCSD Human Subjects Institutional Review Board.
Questionnaire A valid and reliable questionnaire was developed to measure providers’ immunization-relevant knowledge, attitudes, selfefficacy, vested interest, perceived barriers, and practices.28 Knowledge was measured by 14 questions pertaining to the immunization contraindications, schedule, efficacy, and adverse effects (Cronbach’s alpha coefficient of internal consistency, 0.68). Attitudes— defined as the extent of favorable reactions toward having all children properly immunized at every healthcare visit—were assessed by four customarily used items: beneficial, positive, purposeful, and wise (␣⫽0.96). Self-efficacy, defined as belief in one’s personal capability to properly immunize, was measured by two questions about the level of control over and influence on proper immunization (␣⫽0.35). Vested interest, or perceptions of personal professional consequences of immunization, was measured by two questions about the comparative importance of immunization relative to other professional goals and concern about proper immunization (␣⫽0.73). Perceived barriers, or factors hindering proper immunization, were measured on a 16-item scale assessing the seriousness of monetary, logistic, parental, medical, and physician-related barriers (␣⫽0.89). Respondents indicated their answers on a 5-point scale (0⫽not at all, 4⫽extremely), with higher numbers indicating more positive attitudes, stronger self-efficacy and vested interest, and more serious barriers (Table 1). Immunization practices were measured by four items assessing whether it is a provider’s usual practice to immunize during preventive (well-child) care visits, acute care visits,
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Table 2. Self-reported immunization practices: means, standard deviations, and correlations with missed opportunities Immunization practice
Mean
Standard deviation
Immunizing during preventive care visits (1 ⫽ yes; 2 ⫽ no) Immunizing during acute care visits (1 ⫽ yes; 2 ⫽ no) Immunizing during follow-up visits (1 ⫽ yes; 2 ⫽ no) Immunizing during chronic illness visits (1 ⫽ yes; 2 ⫽ no) Likelihood of immunizing an 8-month-old child with a cold who is overdue on immunizations but has an appointment in 1 month for a wellchild visit (1 ⫽ not likely; 5 ⫽ absolutely) Likelihood of deferring one of the immunizations (Hib, DTP/DTaP) for which a 15-month-old presenting for well-child check is due. The child has received OPV3, Hib3, DTP/DtaP3, HepB3, MMR1, and Varicella appropriately (1 ⫽ not likely; 5 ⫽ absolutely)
1.00
0.00
1.21
0.42
1.00
0.00
1.04
0.19
0.15
0.46
4.29
0.98
⫺0.21
0.28
1.14
0.76
⫺0.04
0.85
Correlation (r) — 0.13 —
p value — 0.50 —
DTP/DtaP3, diphtheria–tetanus toxoids pertussis vaccine; HepB3, hepatitis B; Hib3, Haemophilus influenza vaccine; MMR, measles–mumps– rubella vaccine.
follow-up visits, and chronic illness visits. Two additional descriptive questions assessing immunization practices are listed in Table 2. The questionnaire was administered to providers between October 1997 and September 1999.
Missed Opportunities For each provider, a sample was determined that consisted of as many as 47 consecutive visits (mean, 26 visits; median, 22 visits; and range, 14 to 47) within the previous 3 months by children aged up to 2 years. On average, the first and last visits audited occurred at 1.5 months before (mean, 49.80 days) or after (mean, 45.54 days) questionnaire administration. The following information was abstracted from the patient’s medical chart using a structured record assessment tool: immunization history, visit type, temperature, and documented reasons for not immunizing if the patient did not receive a needed vaccine. A visit was considered a missed opportunity if a needed vaccine, as determined by the immunization schedule of the Advisory Committee on Immunization Practices (Centers for Disease Control and Prevention), was not given and no valid reason for the failure to immunize was recorded. If some but not all of the recommended immunizations were given, the visit was still considered to be a missed opportunity. Only the 28 providers who had a minimum of 10 visits by children eligible for immunizations were included in the analysis, as explained above. In addition to computing descriptive statistics, Pearson correlation coefficients were computed to examine the relationship between missed opportunities and each of the remaining variables. The small number of providers prohibited more informative regression analyses.
of vaccination (mean, 0.58; standard deviation [SD] ⫽ 0.18). Missed opportunity rates were 88.4% for acute care visits, 72.1% for follow-up visits, and 39.1% for well-child visits. As indicated in Table 1, providers answered correctly somewhat more than half of the knowledge questions. They expressed, on average, very positive attitudes, strong vested interest and self-efficacy, and perceived relatively weak barriers to immunizations (Table 1). A statistically significant correlation between missed opportunities and vested interest (r ⫽⫺0.45) and a nearly significant correlation between missed opportunities and attitudes (r ⫽⫺0.33) indicated that stronger vested interest and more positive attitudes were associated with lower missed opportunities. Correlations between missed opportunities and knowledge, perceived barriers, and self-efficacy were not significant (Table 1). Providers invariably (100%) responded that it was their usual practice to immunize during preventive and follow-up visits. In addition, a majority responded that they usually immunize during chronic illness– care visits (96.3%) and acute care visits (78.6%). Providers reported that they were very likely to immunize a child with a cold who is overdue on immunizations and unlikely to defer one of the two immunizations for which a child presenting for well-child check is due (Table 2). None of these self-reports on immunization practices was significantly correlated with missed opportunities (Table 2).
Discussion Results On average, healthcare providers missed over half of the opportunities to immunize young children in need
The goal of this pilot study was to examine psychosocial factors predictive of missed opportunities to immunize young children. Of the three types of psychosocial Am J Prev Med 2002;22(3)
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factors (factual knowledge, motivation, and perceived control), only motivational factors proved to be predictive of missed opportunities. Stronger vested interest in immunizations and more positive attitudes toward immunizations were associated with lower rates of missed opportunities. These findings indicate that providers who were concerned about immunization as an important and valued professional goal were more likely to take actions to ensure that all children in their practice were properly immunized at every healthcare visit. Although the correlation between missed opportunities and attitudes did not reach statistical significance in our study, it is noteworthy in light of others’ findings, which indicated that providers’ indifferent attitudes were largely responsible for their missed opportunities to immunize.30 Interestingly, better knowledge did not contribute to lower missed opportunity rates. Because several previous studies suggested that a lack of specific knowledge about contraindications to immunizations may contribute to missed opportunities,14,23–25 we performed an additional analysis correlating missed opportunities with each of the three contraindication questions. Findings, however, were consistent with those for the entire knowledge scale (correlation coefficients ranged between 0.0 and 0.08), indicating that neither general knowledge nor specific knowledge about contraindications contributed to missed opportunities. The stronger predictive value of motivational variables over knowledge variables carries a practical implication for the importance of professional socialization that emphasizes the value of immunization. Socializing providers to value immunization as a professional goal may be equally if not more important than teaching them facts about immunizations. Activities that promote such socialization should be incorporated into existing models of continuing education about vaccine delivery, medical school and primary care curricula, and organizational quality improvement projects focused on immunizations. Lack of association between knowledge and behavior has been documented in many healthcare domains.31 Lack of association, however, does not imply that knowledge is irrelevant. Rather, knowledge about contraindications and other immunization issues is likely a necessary but not sufficient factor to ensure proper immunization. It is plausible that among providers who are knowledgeable about immunizations, only those with strong motivation will translate their knowledge into practice. Similarly, lack of association between perceived control and missed opportunities possibly indicates that among providers who perceive that they have control over immunizations, only those motivated enough will exercise their control to ensure proper immunization. This conjecture is based on previous findings about a relatively modest relationship between any single attitudinal variable and behavior, but a 168
relatively strong relationship between combined attitudinal variables and behavior.32 These interactive effects of motivational and other psychosocial factors should be tested in future studies with substantially larger numbers of providers to allow for regression analysis with interaction terms. Future research should also take into account our finding that self-reports clearly tend to overestimate desirable immunization practices. Because providers either cannot or do not want to report their practices accurately, their self-reports should not be used as a substitute or a proxy for actual practices. Studies that rely on self-reports very likely misrepresent not only actual practice but also its relation to psychosocial factors. This conclusion is supported by our finding that none of the providers in this study reported missing an opportunity to immunize during preventive (well-child) and follow-up care visits; however, over one third of preventive care visits and almost two thirds of follow-up visits in fact reflected missed opportunities. Similarly, few providers reported missing an opportunity to immunize during acute care visits, although our data showed that almost 90% of those visits contained missed opportunities. Self-reports did not prove to be significantly related to actual missed opportunities, suggesting that responses may be driven more by social desirability than awareness of actual practice. An important implication of these findings is that assessing providers’ perceptions of their own practice is a necessary first step in planning intervention strategies. Inaccurate perceptions can then be identified and tactfully presented. Providers who perceive that there is room for improvement are more likely to cooperate in efforts to improve those practices. There are limitations to this pilot study that should be noted. Already mentioned was the small sample size that precluded more powerful multivariate statistical analyses. These analyses, which require a substantially larger sample, would be more informative in that they would allow examination of the combined effects of knowledge, motivation, and perceived control on missed opportunities or the combined effect of these psychosocial characteristics of providers and characteristics of their practices (e.g., size of practice, and number of children seen per week) on missed opportunities. Another limitation of this study is that our convenience sample may not represent the general provider population. The protocol required that providers have at least 10 visits by children eligible for immunizations during the study period. The sample, therefore, might have over-represented providers with relatively poor immunization practices, since providers who kept their patients’ immunizations up to date would have had fewer eligible visits during the observation period. Despite these limitations, this study is among the first to link provider-specific missed opportunities and pro-
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vider-specific psychosocial and practice variables, measured with a carefully developed questionnaire with documented psychometric qualities. Our findings warn against simplistic interventions that target a single factor in an attempt to reduce missed opportunities. Although motivation appears to be the best candidate for a single-factor intervention, our findings suggest that complex interventions that combine multiple factors are more likely to succeed because multiple factors combine to determine missed opportunities. Future studies should help to specify which combinations of factors are the best candidates for reducing missed opportunities.
References 1. The National Vaccine Advisory Committee. Strategies to sustain success in childhood immunizations. JAMA 1999;282:363–70. 2. Zimmerman RK, Burns IT. Child vaccination. Part 1: routine vaccines. J Fam Pract 2000;49(suppl 9):S22–33. 3. Ball TM, Serwint JR. Missed opportunities for vaccination and the delivery of preventive care. Arch Pediatr Adolesc Med 1996;150:858 – 61. 4. Grabowsky M, Orenstein WA, Marcuse EK. The critical role of provider practices in undervaccination. Pediatrics 1996;97:735–7. 5. Orenstein WA, Atkinson W, Mason D, Bernier RH. Barriers to vaccinating preschool children. J Health Care Poor Underserved 1990;1:315–30. 6. Santoli JM, Szilagyi PG, Rodewald LE. Barriers to immunization and missed opportunities. Pediatr Ann 1998;27:366 –74. 7. Wood DL, Brunell PA. Measles control in the United States: problems of the past and challenges for the future. Clin Microbiol Rev 1995;8:260 –7. 8. Centers of Disease Control and Prevention. Impact of missed opportunities to vaccinate preschool-aged children on vaccination coverage levels— selected U.S. sites, 1991–1992. MMWR Morb Mort Wkly Rep 1994;43:709 – 18. 9. Farizo KM, Stehr-Green PA, Markowitz LE, Patriarca PA. Vaccination levels and missed opportunities for measles vaccination: a record audit in a public pediatric clinic. Pediatrics 1992;89:589 –92. 10. Fairbrother G, Friedman S, DuMont KA, Lobach KS. Markers for primary care: missed opportunities to immunize and screen for lead and tuberculosis by private physicians serving large numbers of inner-city Medicaideligible children. Pediatrics 1996;97:785–90. 11. Hutchins SS, Escolan J, Markowitz LE, et al. Measles outbreak among unvaccinated preschool-aged children: opportunities missed by health care providers to administer measles vaccine. Pediatrics 1989;83:369 –74. 12. Szilagyi PG, Rodewald LE, Humiston SG, et al. Missed opportunities for childhood vaccinations in office practices and the effect on vaccination status. Pediatrics 1993;91:1–7; 545. 13. McConnochie KM, Roghmann KJ. Immunization opportunities missed among urban poor children. Pediatrics 1992;89:1019 –26.
14. Szilagyi PG, Rodewald LE. Missed opportunities for immunizations: a review of the evidence. J Public Health Manag Pract 1996;2:18 –25. 15. Holt E, Guyer B, Hughart N, et al. The contribution of missed opportunities to childhood underimmunization in Baltimore. Pediatrics 1996;97: 474 – 80. 16. Sabnis SS, Pomeranz AJ, Lye PS, Amateau MM. Do missed opportunities stay missed? A 6-month follow-up of missed vaccine opportunities in inner city Milwaukee children. Pediatrics 1998;101:E5. Available at: www.pediatrics.org. 17. Szilagyi PG, Roghmann KJ, Campbell JR, et al. Immunization practices of primary care practitioners and their relation to immunization levels. Arch Pediatr Adolesc Med 1994;148:158 – 66. 18. Weese CB, Krauss MR. A “barrier-free” health care system does not ensure adequate vaccination of 2-year-old children. Arch Pediatr Adolesc Med 1995;149:1130 –5. 19. Wood D, Pereyra M, Halfon N, Hamlin J, Grabowsky M. Vaccination levels in Los Angeles public health centers: the contribution of missed opportunities to vaccinate and other factors. Am J Public Health 1995;85:850 –3. 20. Wood D, Schuster M, Donald-Sherbourne C, Duan N, Mazel R, Halfon N. Reducing missed opportunities to vaccinate during child health visits: how effective are parent education and case management? Arch Pediatr Adolesc Med 1998;152:238 – 43. 21. Yawn BP, Kurland M, Boloton R, Martin AR. Immunization compliance outside the health plans: a non-HMO report card. Minn Med 1995;78:25– 32. 22. Dietz VJ, Stevenson J, Zell ER, Cochi S, Hadler S, Eddins D. Potential impact on vaccination coverage levels by administering vaccines simultaneously and reducing dropout rates. Arch Pediatr Adolesc Med 1994;148: 943–9. 23. Hutchins SS, Jansen HA, Robertson SE, Evans P, Kim-Farley RJ. Studies of missed opportunities for immunization in developing and industrialized countries. Bull World Health Organ 1993;71:549 – 60. 24. Pritchard M, Bell LM, Levenson R. Inpatient immunization program: eliminating a missed opportunity. Pediatr Nurs 1995;21:453–7. 25. Gamertsfelder DA, Zimmerman RK, DeSensi EG. Immunization barriers in a family practice residency clinic. J Am Board Fam Pract 1994;7:100 – 04. 26. Smith SW, Connery P, Knudsen K, et al. Immunization practices and beliefs of physicians in suburban Cook County, Illinois. J Community Health 1999;24:1–11. 27. Ajzen I. The theory of planned behavior. Organizational Behav Hum Decis Processes 1991;50:179 –211. 28. Prislin R, Nader PR, De Guire M, et al. Physicians’ immunization knowledge, attitudes, and practices: a valid and internally consistent measurement tool. Am J Prev Med 1999;17:151–2. 29. Department of Health and Human Services, Health Resources and Service Administration. Lists of designated primary medical care, mental health, and dental health professional shortage areas—HRSA. Notice. Federal Register 1995;60:51518 – 655. 30. Mitra J, Manna A. An assessment of missed opportunities for immunization in children and pregnant women attending different health facilities of a state hospital. Indian J Public Health 1997;41:31–2. 31. Stroebe W, Stroebe MS. Social psychology and health. Pacific Grove, CA: Brooks/Cole, 1995. 32. Kraus SJ. Attitudes and the prediction of behavior: a meta-analysis of the empirical literature. Personality Social Psychol Bull 1995;21:58 –75.
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