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Table 3 Conditional logistic regression analysis

From: Why do hospital prescribers continue antibiotics when it is safe to stop? Results of a choice experiment survey

Attribute2CoefficientSELower CIUpper CIAverage marginal effect (AME)1p
 UTI symptoms with kidney pain1.1320.1550.8291.4360.173< 0.001
 Fever, cough and possible pulmonary infiltrates on chest X-ray0.2460.1080.0340.4590.0380.023
 Unclear symptoms3− 1.379
 Strongly conflict1.2750.1311.0181.5320.194< 0.001
 Somewhat conflict0.0730.089− 0.1010.2480.0110.411
 No conflict3− 1.348
CONTINUE RISK− 0.0850.012− 0.108− 0.061− 0.013< 0.001
STOP RISK0.1720.0170.1390.2050.026< 0.001
 Severe frailty and comorbidities0.6600.1380.3900.9300.101< 0.001
 Moderate frailty and comorbidities0.3000.0980.1080.4920.0460.002
 Fit and well3− 0.960
 No pressure− 0.6600.097− 0.851− 0.469− 0.101< 0.001
 Some pressure− 0.1040.094− 0.2890.080− 0.0160.268
 Heavy pressure30.764 
 McFadden’s R2 (pseudo-R2)0.320     
 Log-likelihood− 478.384     
  1. 1AME is the average marginal effect of each factor level on the probability of choosing to continue. For the categorical factor levels, this indicates how much higher/lower the probability of continuing was at this attribute level than the probability at the factor’s base level. For the continuous variables (risk of continuing/risk of discontinuing), the AME indicates how much higher/lower the probability of continuing was for a 1% higher risk. AIC Akaike Information Criterion, BIC Bayesian Information Criterion, CI 95% confidence interval. p p value of coefficient, SE standard error clustered at the respondent level
  2. 2Attribute descriptions: SYMPTOMS = patient’s presenting symptoms (1 = UTI and kidney, 2 = fever cough and funny X-ray, 3 = unclear [base level]); CONFLICT WITH GUIDELINES = whether early discontinuation of antibiotic treatment within 72 h of treatment initiation would be in conflict with local antibiotic guidelines (1 = strongly conflict, 2 = somewhat conflict, 3 = not conflict [base level]); CONTINUE RISK = risk of significant harm arising from continued antibiotic treatment, expressed as a percentage; STOP RISK = risk of significant harm arising from discontinuing antibiotic treatment, expressed as a percentage; PREMORBID CONDITION = premorbid condition of the patient (1 = severe frailty and comorbidities, 2 = moderate frailty and comorbidities, 3 = fit and well [base level]); and EXTERNAL PRESSURE = level of external pressure to continue antibiotic treatment (1 = no pressure, 2 = some pressure, 3 = heavy pressure [base level]). The sample size arises from 98 respondents times 15 choice questions. The 2 respondents who chose ‘continue’ in all 15 choice questions were omitted because of the lack of variation in their responses
  3. 3These attributes were effects-coded. The coefficients of the base levels (unclear symptoms, no conflict, fit and well and heavy pressure) were calculated as the negative sum of the coefficients of the other levels