TY - JOUR
T1 - Defining antimicrobial prescribing quality indicators: what is a new prescription?
AU - Boesten, Jos
AU - Harings, Luc
AU - Winkens, Bjorn
AU - Knottnerus, Andre
AU - van der Weijden, Trudy
PY - 2011/1
Y1 - 2011/1
N2 - Since guidelines on antibiotic drug treatment often focus on appropriate first choice drugs, assessment of guideline adherence should only concentrate on the first drug prescribed, and not on subsequent antibiotics prescribed after failure of the first one. Purpose To determine a valid cut-off point for a definition of "first" or "new" prescription in indicators for the assessment of the quality of antibiotic drug treatment on the basis of pharmaceutical data. Methods Three possible definitions for the term "new prescription" were compared, based on three different periods of time, viz. more than 35, 28, or 21 days after starting a previous antibiotic. In an observational study, 1,225 antimicrobial prescriptions from the medical files of five family practices were audited ("clinical classification") and compared with a classification based on the three definitions ("technical classification"). Agreement between these clinical and technical classifications was determined by calculating Cohen's kappa. The technical classification was analyzed as a diagnostic test, using the clinical classification as the gold standard, and sensitivity, specificity, likelihood ratios, and post-test probabilities were calculated. Results Defining "new prescription" as "more than 35 days after a previous prescription was issued" resulted in a Cohen's kappa of 0.93 (95% CI 0.92-0.98). The diagnostic value of this definition was extremely high, with a sensitivity of 0.976, specificity of 0.987, positive likelihood ratio of 77.7, and negative likelihood ratio of 0.02. Conclusion We recommend using a cut-off value of 35 days since the last antimicrobial prescription as the definition of a "new prescription" when no diagnostic information is available, i.e., when using pharmaceutical data to assess the quality of antibiotic prescribing behavior.
AB - Since guidelines on antibiotic drug treatment often focus on appropriate first choice drugs, assessment of guideline adherence should only concentrate on the first drug prescribed, and not on subsequent antibiotics prescribed after failure of the first one. Purpose To determine a valid cut-off point for a definition of "first" or "new" prescription in indicators for the assessment of the quality of antibiotic drug treatment on the basis of pharmaceutical data. Methods Three possible definitions for the term "new prescription" were compared, based on three different periods of time, viz. more than 35, 28, or 21 days after starting a previous antibiotic. In an observational study, 1,225 antimicrobial prescriptions from the medical files of five family practices were audited ("clinical classification") and compared with a classification based on the three definitions ("technical classification"). Agreement between these clinical and technical classifications was determined by calculating Cohen's kappa. The technical classification was analyzed as a diagnostic test, using the clinical classification as the gold standard, and sensitivity, specificity, likelihood ratios, and post-test probabilities were calculated. Results Defining "new prescription" as "more than 35 days after a previous prescription was issued" resulted in a Cohen's kappa of 0.93 (95% CI 0.92-0.98). The diagnostic value of this definition was extremely high, with a sensitivity of 0.976, specificity of 0.987, positive likelihood ratio of 77.7, and negative likelihood ratio of 0.02. Conclusion We recommend using a cut-off value of 35 days since the last antimicrobial prescription as the definition of a "new prescription" when no diagnostic information is available, i.e., when using pharmaceutical data to assess the quality of antibiotic prescribing behavior.
KW - Quality indicators, health care
KW - Primary health care
KW - Prescriptions
KW - Guideline adherence
U2 - 10.1007/s00228-010-0909-z
DO - 10.1007/s00228-010-0909-z
M3 - Article
C2 - 20941487
SN - 0031-6970
VL - 67
SP - 91
EP - 96
JO - European Journal of Clinical Pharmacology
JF - European Journal of Clinical Pharmacology
IS - 1
ER -