Cost-effectiveness analysis of five different antibiotic regimens for the treatment of uncomplicated Chlamydia trachomatis cervicitis.

BACKGROUND: The new Centers for Disease Control and Prevention treatment guidelines for Chlamydia trachomatis include two recently available drugs, azithromycin and ofloxacin. The best choice for initial therapy remains controversial. OBJECTIVES: We wanted to perform a cost-effectiveness analysis of five different antibiotic regimens for the treatment of uncomplicated Chlamydia trachomatis cervicitis. METHODS: Using information gathered from a MEDLINE search of the English language literature from 1966 to 1994, employing the key words "cervicitis," "C. trachomatis," "erythromycin," "tetracycline," "doxycycline," "ofloxacin," and "azithromycin," we developed a decision analysis model specific for a nonpregnant woman with uncomplicated Chlamydia trachomatis cervicitis. Options in this model included an initially cured infection, a failed initial cure resulting in persistent cervicitis, or pelvic inflammatory disease treated either on an inpatient or outpatient basis. Probability estimates for each option were derived from previously published reports. A cost-effectiveness analysis was performed for three end points: cost per cure with initial therapy, cost per case of pelvic inflammatory disease averted, and cost per hospitalization averted. Sensitivity analyses were done by varying the cure rates for each antibiotic and the complication rates for failed therapy. The costs incurred for treatment were also varied. RESULTS: Using the high estimate for initial cure rates, doxycycline and tetracycline were the most cost-effective agents. Azithromycin was the next most cost-effective agent, followed by ofloxacin and erythromycin. To achieve an equivalent final cost, the probability of initial cure with azithromycin must exceed that of doxycycline by 3 percentage points. As the cost of azithromycin decreases, the difference in initial cure rates between the two drugs to achieve an equivalent final cost becomes smaller. CONCLUSIONS: Doxycycline remains the drug of choice in the treatment of Chlamydia trachomatis cervicitis. The results favor the use of azithromycin rather than doxycycline when there is concern for compliance to the standard doxycycline regimen. A lower cost for azithromycin could favor its use as the drug of choice.

Multiple regression for molecular-marker, quantitative trait data from large F2 populations.

Molecular marker-quantitative trait associations are important for breeders to recognize and understand to allow application in selection. This work was done to provide simple, intuitive explanations of trait-marker regression for large samples from an F2 and to examine the properties of the regression estimators. Beginning with a(- 1,0,1) coding of marker classes and expected frequencies in the F2, expected values, variances, and covariances of marker variables were calculated. Simple linear regression and regression of trait values on two markers were computed. The sum of coefficient estimates for the flanking-marker regression is asymptotically unbiased for an included additive effect with complete interference, and is only slightly biased with no interference and moderately close (15 cM) marker spacing. The variance of the sum of regression coefficients is much more stable for small recombination distances than variances of individual coefficients. Multiple regression of trait variables on coded marker variables can be interpreted as the product of the inverse of the marker correlation matrix R and the vector a of simple linear regression estimators for each marker. For no interference, elements of the correlation matrix R can be written as products of correlations between adjacent markers. The inverse of R is displayed and used to illustrate the solution vector. Only markers immediately flanking trait loci are expected to have non-zero values and, with at least two marker loci between each trait locus, the solution vector is expected to be the sum of solutions for each trait locus. Results of this work should allow breeders to test for intervals in which trait loci are located and to better interpret results of the trait-marker regression.

Initiation of a clinical pharmacology consult service as a formulary management tool.

Establishment of a multidisciplinary clinical pharmacology consult service (CPCS) can be an important adjunct to a successful formulary management system. This article describes the model of a CPCS developed at the University of California Davis Medical Center. The CPCS provides patient-specific consultations, serves a leadership role in directing the medical staff toward hospital-wide drug usage guidelines for high cost pharmaceutical agents, and enforces the P & T Committee adopted criteria on selected high-cost or high risk agents. The mission of the CPCS is to provide the P & T Committee with a multidisciplinary mechanism to educate health care providers, improve patient care, establish drug usage criteria, and enforce those criteria.

Use of RFLP markers to search for alleles in a maize population for improvement of an elite hybrid.

Molecular markers can be used to detect alleles in donor genetic material for improvement of existing cultivars or hybrids. DNA restriction fragment length polymorphisms (RFLPs) were used as markers to search for favorable alleles at quantitative trait loci in the maize (Zea mays L.) population BS11(FR)C7 which were not in the hybrid 'FRB73 x FRMo17.' Thirty-four RFLP markers were used to determine RFLP 'fingerprints' for 220 [BS11(FR)C7 x FRMo17] F2 individuals; multiple morphs (bands) were observed at most markers. Statistical associations between RFLPs and trait expression in F2 x FRB73 progeny were found for grain yield, stalk and root lodging, plant and ear height, maturity, and seven grain yield component traits. Associations were found using linear contrasts among RFLP marker classes to estimate trait effects. Estimated effects for grain yield ranged from 213 to 538 kg ha(-1), 3.0-7.5% of the experimental mean, respectively. RFLP markers with greatest probability of association with grain yield were NPI234 (short arm of chromosome 1) and UMC16 (long arm of chromosome 3). Digenic epistasis appeared to be important in grain yield expression, as indicated by a 12% increase in the proportion of genotypic variation accounted for when significant di-marker interactions were added to a linear model, including all markers individually associated with grain yield. The majority of interactions associated with grain yield involved markers NPI234 and UMC21 (long arm of chromosome 6). Many RFLP markers were associated with multiple traits. At some markers, the same bands were associated with favorable effects for stalk lodging, grain yield, and yield components. RFLP bands unique to BS11(FR)C7 showed associations favorable over those from FRMo17 for at least one marker in all but one trait. The results of this study will be useful in future RFLP marker-assisted selection programs aimed at developing lines for improved performance in combination with FRB73.