International Journal for Quality in Health Care 16:245-251 (2004)
International Journal for Quality in Health Care vol. 16 no. 3 © International Society for Quality in Health Care and Oxford University Press 2004; all rights reserved
Physician knowledge and adherence to prescribing antibiotic prophylaxis for sickle cell disease
University of North Carolina School of Pharmacy and School of Public Health, University of North Carolina, Chapel Hill, NC, USA
Objective. The purpose of this research was to examine how physician characteristics were associated with: (i) physician knowledge of and adherence to sickle cell guidelines; and (ii) the types of educational programs about sickle cell disease desired by physicians.
Methods. A survey was developed to assess the research objective. After the survey was pre-tested and an institutional review board exemption was obtained, it was sent to a systematic random sample of 375 pediatricians and all 125 practicing hematologists in North Carolina. They were asked to answer a six-item knowledge test relating to the antibiotic prophylaxis guidelines.
Results. The response rate was 57%, of which 61% were pediatricians. Over half (56%) were in a practice with at least one pediatric sickle cell patient. Fifty-nine percent of physicians answered five or more questions correctly on the knowledge test. The question most physicians answered correctly (97%) pertained to the necessity of antibiotics for children with sickle cell disease. The question most frequently answered incorrectly (62%) pertained to prescribing antibiotics to a child with unconfirmed sickle cell disease. Logistic regression results indicated that the number of sickle cell patients seen in practice influenced the number of questions answered correctly. Sixty-six percent of physicians prescribed prophylactic antibiotics for 100% of their patients with sickle cell disease and therefore were 100% adherent. Eighty-one percent of pediatricians compared with 12% of hematologists were 100% adherent in prescribing antibiotics. Hematologists and those practicing at a medical school or university were less likely to be 100% adherent in prescribing antibiotic prophylaxis.
Conclusion. The majority of physicians surveyed were relatively knowledgeable about sickle cell guidelines, however there may be a need for continuing education programs that focus on the issues of prescribing antibiotics to a child with unconfirmed sickle cell disease and penicillin dosage.
Keywords: antibiotic prophylaxis, continuing education, physician adherence, physician knowledge, sickle cell disease
Address reprint requests to Keele E. Wurst, University of North Carolina at Chapel Hill, School of Pharmacy, Beard Hall, CB #7630, Chapel Hill, NC 27599-7630, USA. E-mail: keele_wurst{at}unc.edu or keelevan{at}email.unc.edu
Accepted for publication December 10, 2003.
Sickle cell disease is a potentially fatal disease, striking one in every 375 African-American children [1]. Children with sickle cell disease under the age of 5 years are at great risk for fatal invasive infection with Streptococcus pneumoniae and Haemophilus influenzae due to the inability of their spleen to protect against infection [2,3]. Randomized, controlled trials have demonstrated that a twice-daily dose of penicillin prophylaxis until the age of 5 years reduces the incidence of septicemia by 84% [4]. Studies have indicated that the rate at which sickle cell patients receive antibiotic prophylaxis is typically less than optimal [5–7]. There are two main reasons why patients do not receive antibiotic prophylaxis: (i) physicians do not prescribe the antibiotics; and (ii) the patient does not take the antibiotics. This study focuses on physician prescribing of antibiotic prophylaxis.
Clinical practice guidelines to prescribe antibiotic prophylaxis for patients with sickle cell disease have been created and disseminated in the hope that physicians will follow them as stated to ensure best clinical practice. However, many physicians are unaware of or are not influenced by the guidelines [8]. There have been many reasons postulated as to why physicians do not follow guidelines.
Factors that have been shown to positively influence physician adherence to guidelines include female gender, younger age, awareness and agreement with guidelines, and larger practice size [9–11]. In a study performed to assess adherence to guidelines regarding cancer screening, the physician characteristics that influenced adherence to guidelines included: agreement with guidelines, level of continuing medical education, and perceived probability of the disease [9]. The characteristics associated with disagreement with guidelines, and consequently non-adherence, included older age, male sex, and not having completed a postgraduate residency program [9]. Practice characteristics that affected adherence to guidelines included type of practice (group or solo), payment system, perceived time to perform the test, access to current information, and the costs of the testing [9]. Physicians may also not follow the guidelines by prescribing incorrectly for the disease, such as prescribing antibiotic prophylaxis therapy for a patient with sickle cell trait instead of sickle cell disease. There are many causes of inappropriate prescribing, including the physician’s knowledge base (the physician’s knowledge on up-to-date therapeutics) and physician practice patterns (type of practice, payment schedule, number of physicians in practice) [12]. Some of these causes may contribute to lack of adherence to the guidelines and thus inadequate prescribing for sickle cell disease.
Physician awareness of guidelines, agreement with guidelines, and knowledge of the content of the guidelines are also important in assessment of adherence to guidelines. In a study of adherence to guidelines for cesarean section, Lomas et al. demonstrated that awareness and agreement with guidelines did not lead to adherence to the guideline. Poor knowledge of the contents of the guidelines was associated with poor guideline adherence [13].
We are not aware of any studies performed with the intention of understanding physicians’ attitudes toward the guideline for prescribing for sickle cell patients and examining the physicians’ adherence to the guideline for prescribing sickle cell prophylaxis. Understanding physician characteristics that are associated with adherence to guidelines can help to create better educational programs for physicians. Therefore, the purpose of this study was to examine: (i) how physician gender, age, awareness of the North Carolina Sickle Cell Syndrome Program (NCSCSP), and practice size were associated with physician knowledge of sickle cell guidelines to prescribe prophylactic antibiotics for sickle cell disease; and (ii) to describe how physician gender, age, practice specialty, physician knowledge, and number of sickle cell patients contributed to physician adherence to antibiotic prophylaxis-prescribing guidelines.
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Methods |
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The study was a cross-sectional survey of North Carolina hematologists, hematology/oncologists, and pediatricians. Information on the providers was obtained from the 1999 North Carolina Health Professions Data System [14]. A knowledge questionnaire, which consisted of six items relating to sickle cell disease and adherence to antibiotic prophylaxis, was included in the survey.
After obtaining an institutional review board (IRB) exemption, all questions included in the survey were pre-tested on three physicians (a hematologist, a pediatrician, and a general practitioner) and were subsequently modified for clarity. The survey questionnaire for the study is available as Supplementary data, available at IJQHC Online. The survey was sent to 500 physicians: all 125 hematologists/oncologists practicing in North Carolina and a stratified random sample of 375 pediatricians. The sampling frame included all pediatricians who practiced in a North Carolina county where >20% of the population was non-white in order to target those who most likely cared for patients with sickle cell disease. The pediatricians included in the sampling frame were sampled by random number until a sample of 375 was obtained. Four weeks after the survey had been mailed, the survey was re-sent to non-responders. A monetary incentive of US$1 was included with the survey to improve the response rate [15].
Measures
Physician age, years in practice, number of sickle cell patients in practice, and number of sickle cell patients <5 years of age in practice were measured as continuous variables. Physician gender, race (white and non-white), and practice specialty (pediatrics and hematology) were measured as dichotomous variables. Practice setting was measured as a categorical variable (group office, hospital setting, medical school, and other).
Physicians were first asked demographic questions and if they cared for sickle cell patients under the age of 5 years. Physicians who did care for sickle cell patients were asked ‘For what percentage of sickle cell disease patients seen in practice have you prescribed antibiotic prophylaxis?’. Since the guideline states that a patient with sickle cell disease should be prescribed antibiotic prophylaxis, this question was used as a surrogate measure of physician adherence to guidelines [1]. Physicians were asked a series of six questions to determine their knowledge of the contents of the sickle cell disease guidelines (Table 1). Physicians were also asked to rate their method of preference for receiving continuing education on sickle cell disease.
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Analysis
The survey data were analyzed using SPSS statistical software (SPSS version 10, 2000; SPSS, Chicago, IL). Bivariate analyses, including 
2 and t-tests, were conducted to assess the relationships between the physician demographic and practice characteristics, physician knowledge, and physician adherence to the guidelines. Multivariate logistic regressions were conducted to: (i) predict if the number of sickle cell patients seen, practice specialty, race, years in practice, gender, and awareness of the sickle cell program influenced physician knowledge of the sickle cell guidelines; and (ii) determine if age, practice setting, practice specialty, years in practice, and physician knowledge were associated with physician adherence to the sickle cell guidelines.
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Results |
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Of the 500 surveys mailed, 64 (50 pediatricians and 14 hematologists) were returned because of incorrect addresses and were discarded. Two hundred and forty-eight responses were returned (overall response rate = 57%). Among pediatricians the response rate was 59% (n = 191), and among hematologists the response rate was 51% (n = 57). Table 2 presents respondent characteristics. The majority of respondents were white, male, aged from 30 to 76 years (mean 47 years), and specialized in pediatrics. The characteristics of gender, race, age, practice setting, and practice specialty of the respondents and non-respondents were not significantly different. Over half (137 out of 248) of the responding physicians cared for sickle cell patients under the age of 5 years. In the six-item test, a physician was considered to have complete knowledge of the sickle cell guidelines if he/she answered five or six of the six questions correctly. Table 1 demonstrates the number of questions physicians answered correctly. Sixty-four percent of physicians answered five or more questions correctly. The question most physicians answered correctly (96.4%) addressed the necessity of antibiotics for children with sickle cell disease. Ninety-seven percent of physicians knew that children with sickle cell disease trait should not be on antibiotic prophylaxis. The question most frequently answered incorrectly (50.8%) pertained to prescribing antibiotics to a child with unconfirmed sickle cell disease. Questions about penicillin dosages were also frequently answered incorrectly. For all questions answered, a greater percentage of physicians answered the question correctly than answered incorrectly.
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The results of the logistic regression indicated that pediatric specialty was associated with answering five or six out of six questions correctly. Table 3 presents the multivariate regression statistics. Pediatric specialty was associated with whether the physician was knowledgeable about the sickle cell guidelines in both the bivariate and the multivariate analysis. Pediatricians were more likely than hematologists to answer five or six out of six questions correctly. Gender was significantly associated with the number of questions answered correctly in the bivariate analysis, but was not significantly associated when other variables were added to the model. An interaction term of practice specialty and number of sickle cell disease patients seen in practice was statistically significant in the multivariate model. This term indicates that a hematologist who saw more patients with sickle cell disease was more likely to answer five or six out of six questions correctly than hematologists who saw fewer patients with sickle cell disease. Number of sickle cell disease patients in practice, years in practice, race, and awareness of the North Carolina sickle cell syndrome program were not associated with physician knowledge of the guidelines.
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Sixty-six percent of physicians stated that they prescribed prophylactic antibiotics for 100% of their patients with sickle cell disease and were therefore 100% adherent. Five percent were 75–99% adherent, 3% were 25–49% adherent, 2% were 1–24% adherent, and 21% reported that the question was not applicable because they did not prescribe antibiotic prophylaxis. Eighty-one percent of pediatricians compared with 12% of hematologists were 100% adherent in prescribing antibiotics (2 = 46.12; P = 0.000). Seventy-five percent of physicians in group practice, 70% of those in hospital practice, 12.5% of those in medical school practice, and 69.2% of those in other practice settings were 100% adherent in prescribing antibiotics (2 = 12.94; P = 0.005). Eighty-four percent of females and 56.9% of males were 100% adherent in prescribing antibiotics (2 = 11.34; P = 0.001). Younger physicians were significantly more likely to be 100% adherent in prescribing antibiotics compared with older physicians (t = –2.16).
Table 4 presents the knowledge questions alongside the percentage of physicians who answered the questions correctly and were also 100% adherent in prescribing antibiotic prophylaxis.
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Table 5 presents the results of the multivariate logistic regression predicting physician adherence to guidelines. Pediatricians were significantly more likely to be 100% adherent in prescribing antibiotic prophylaxis than hematologists. Physician knowledge of antibiotic prophylaxis-prescribing guidelines was also shown to be associated with physician adherence to prescribing antibiotic prophylaxis. The number of questions answered correctly was significantly associated with physician adherence to guidelines in the bivariate and multivariate analyses.
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Those that practice in a medical school or university were significantly less likely to be 100% adherent in prescribing antibiotic prophylaxis. Gender was significantly associated with adherence in prescribing antibiotic prophylaxis in the bivariate analysis, but not in the multivariate analysis. Years in practice was not associated with a physician being 100% adherent in prescribing antibiotic prophylaxis.
Thirty-eight percent of physicians thought that continuing education programs about sickle cell disease would be most useful in helping them learn more about sickle cell disease, 32% thought mailings on sickle cell disease would be most useful, 13% thought that an e-mail address where the physician could ask questions would be most useful, and <1% thought that it would be useful to have a sickle cell educator contact them at their practice. Thirteen percent had no need for further education in the area of sickle cell disease.
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Discussion |
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TopMethodsResultsDiscussionConclusionReferences |
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Sixty-four percent of the physicians sampled answered five or six out of six questions correctly. This shows that the majority of physicians surveyed were relatively knowledgeable about sickle cell guidelines. The current guidelines state that a child with suspected sickle cell disease should be placed on antibiotics. Many physicians disagreed. This issue needs to be examined further to assess the reasons behind this finding. The emergence of penicillin-resistant pneumococcal infection in children with sickle cell disease may play a role in physician disagreement with guidelines. There has been concern that prophylaxis may favor the development of resistant organisms, therefore some physicians may decide to wait until sickle cell disease is confirmed before prescribing antibiotic prophylaxis [16].
A frequently missed question addressed correct dosages of penicillin for prophylaxis for children under the ages of 5 and 3 years. Many physicians did not know the correct dosage or disagreed with the current recommendations. Pediatric specialty and hematology practices with a greater number of sickle cell disease patients were both significantly associated with answering five or six out of six questions correctly. In this sample, pediatricians were more likely to see patients with sickle cell disease. Therefore this would explain why those in pediatric practice were more likely to be knowledgeable about the guidelines. It is also likely that a hematologist with more patients with sickle cell disease would likely be more knowledgeable about the guidelines. Studies assessing adherence to guidelines showed that older age, male gender, and practice size contributed to non-adherence to guidelines [9]. These factors were not associated with knowledge of guidelines. This may have been due to the way knowledge was measured, as knowledge was only measured by six specific questions. The questions on the survey may not have reflected the true knowledge level of the physician.
This study found that gender was significantly associated with adherence to guidelines in the bivariate model. This study found a significant relationship between practice specialty and adherence to guidelines, as 81% of pediatricians compared with 12% of other practice specialties indicated that they were 100% adherent in prescribing antibiotics. In this subset of physicians surveyed, pediatricians cared for most of the sickle cell disease patients under 5 years of age, which could explain why they were most likely to adhere to the guidelines.
Physician knowledge was also significantly associated with physician adherence to antibiotic prophylaxis-prescribing guidelines. This finding is intuitive as it is to be expected that the more a physician knows about a guideline, the more adherent that physician would be to the guideline.
Those that practiced in a medical school or university setting were significantly less likely to be adherent to guidelines than those in other practice specialties. The opposite would be expected as these physicians work in an environment where guidelines are often developed. Future research could determine the reasons behind this and whether in fact these physicians are actually less adherent to the sickle cell disease guidelines in practice than others.
Less than half of physicians (38%) indicated that continuing education in sickle cell disease would be useful to them in their practice. This could have occurred for three reasons: (i) the physicians surveyed do not see pediatric patients with sickle cell disease and therefore do not have use for a continuing education program; (ii) those in group practices run by HMOs, and those in hospital or medical school practice may receive continuing education programs provided by their employers; and (iii) the physicians surveyed may have much experience with sickle cell disease and do not feel as though they need continuing education. Based on the practice characteristics of the survey respondents, the first reason is the most plausible. The majority of hematology/oncology specialists saw only adult patients (only 18% had a pediatric patient with sickle cell disease in their practice) and only two pediatric hematology/oncology specialists were captured in the sample, therefore adult hematology/oncology specialists would see less need to learn more about pediatric sickle cell disease. Further research may be necessary to understand the true causes for the lack of desire for continuing education in sickle cell disease.
The study had several limitations. One limitation is that the pediatrician survey population only consisted of those that practice in an area where the population is >20% non-white. In limiting the sample population, some of the providers that see patients with sickle cell disease may have been missed. These providers may have different characteristics from the ones surveyed. However, this strategy is also a strength because it is likely that more providers that see patients with sickle cell disease were captured due to the higher percentage of non-whites in the county population.
Although the response rate of 57% in this study is less than ideal, it is above the mean response rate of published physician surveys (54%) [17]. It is likely that those physicians who responded saw more patients with sickle cell disease, although this could not be measured and therefore introduces possible non-response bias into the study. However, factors that could be assessed showed no significant difference between respondents and non-respondents.
In using a cross-sectional study design it is difficult to assess causal relationships between factors in the study. Actual practice and relationships between factors cannot be assessed. Even though this study design is limited, it provides us with an estimate of the physician characteristics that are associated with adherence and knowledge of the sickle cell disease guidelines.
In this study, the assessment of adherence to guidelines is a surrogate measure. It has been shown that self-reported guideline adherence rates exceed those that are objectively measured [18]. Social acceptability bias may also contribute to an increased rate of self-reported adherence. Although we did not have an objective measure of adherence, we did receive an estimate of physician adherence and knowledge of the sickle cell disease guidelines. Future research can build upon this study and use objective measures of guideline adherence from pharmacy records, physician charts, and patient assessments.
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Conclusion |
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TopMethodsResultsDiscussionConclusionReferences |
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The majority of physicians surveyed were relatively knowledgeable about sickle cell guidelines. Physician knowledge of antibiotic prophylaxis-prescribing guidelines was shown to be associated with physician adherence to the guideline. To increase adherence to the guidelines, specific issues of prescribing antibiotics to a child with unconfirmed sickle cell disease and penicillin dosage may need to be addressed, as physicians surveyed were less knowledgeable about these areas.
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References |
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- Sickle Cell Disease Guideline Panel. Sickle Cell Disease: Screening, Diagnosis, Management, and Counseling in Newborns and Infants. Clinical Practice Guideline No. 6. Agency for Health Care Policy and Research (AHCPR) publication No. 93-0562. Rockville, MD: AHCPR, Public Health Service, US Department of Health and Human Services, 1993.
- Stern KS, Davis JG. Newborn Screening for Sickle Cell Disease: Issues and Implications. New York, NY: Council of Regional Networks for Genetic Services, Cornell University Medical College, 1984.
- Overturf GD. Infections and immunizations of children with sickle cell disease. Adv Pediatr Infect Dis 1999; 14: 191–218.[Medline]
- Gaston MH, Veter JL, Woods G et al. Prophylaxis with oral penicillin in children with sickle cell anemia: a randomized trial. N Engl J Med 1986; 314: 1593–1599.[Abstract]
- Teach SJ, Lillis KA, Grossi M. Compliance with penicillin prophylaxis in patients with sickle cell disease. Arch Ped Adoles Med 1998; 152: 274.
- Berkovitch M, Papadouris D, Shaw D, Onuaha N, Dias C, Olivieri NF. Trying to improve compliance with prophylactic penicillin therapy in children with sickle cell disease. Br J Clin Pharmacol 1998; 45: 605–607.[CrossRef][Web of Science][Medline]
- Davis H. Use of computerized health claims data to monitor compliance with antibiotic prophylaxis in sickle cell disease. Pharmacoepidemiol Drug Saf 1998; 7: 107–112.[Medline]
- Pathman D, Konrad T, Freed G, Freeman V, Koch G. The Awareness-to-Adherence model of the steps to clinical practice guideline compliance: the case of pediatric vaccine recommendations. Med Care 1996; 34: 873–889.[CrossRef][Web of Science][Medline]
- Tudiver F, Herbert C, Goel V. Why don’t family physicians follow clinical practice guidelines for cancer screening? Can Med Assoc J 1998; 159: 797–798.[Medline]
- Ely JW, Goerdt CJ, Bergus GR, West CP, Dawson JD, Doebbeling BN. The effect of physician characteristics on compliance with adult preventative care guidelines. Fam Med 1998; 30: 34–39.[Medline]
- Cabana MD, Rand CS, Powe NR et al. Why don’t physicians follow clinical practice guidelines?: a framework for improvement. J Am Med Assoc 1999; 282: 1458–1465.
[Abstract/Free Full Text] - Lexchin J. Improving the appropriateness of physician prescribing. Int J Health Serv 1998; 28: 253–267.[Web of Science][Medline]
- Lomas J, Anderson GM, Dominick-Pierre K, Vayda E, Enkin MW, Hannah WJ. Do practice guidelines guide practice? The effect of a consensus statement on the practice of physicians. N Engl J Med 1989; 321: 1306–1311.[Abstract]
- Sheps Center Data Sources. North Carolina Health Professions Data Book. Sheps Center Data Sources, 1999 (http://www.shepscenter.unc.edu/data/datatoc.html).
- Van Geest J, Wynia M, Cummins D, Wilson I. Effects of different monetary incentives on the return rate of a national mail survey of physicians. Med Care 2000; 39: 197–201.
- Wang WC, Wong W, Rogers ZR, Williams JA, Buchanan GR, Powars DR. Antibiotic-resistant pneumococcal infection in children with sickle cell disease in the United States. J Pediatr Hematol Oncol 1996; 18: 140–144.[CrossRef][Web of Science][Medline]
- Asch DA, Jedrzieski MK, Christakis NA. Response rates to mail surveys published in medical journals. J Clin Epidemiol 1997; 50: 1129–1136.[CrossRef][Web of Science][Medline]
- Adams AS, Soumerai SB, Lomas J, Ross-Degnan D. Evidence of self-report bias in assessing adherence to guidelines. Int J Qual Health Care 1999; 11: 187–192.
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