Table 1.

Reasons for Attrition of Cases

Target Population	No.	%
Patients with ICD9-diagnosis of CAP during the enrollment window (June 30, 2011–May 30, 2015)
Patients with ≥1 prescription fill for any of the 9 antibiotics of interest (amoxicillin, amoxicillin-clavulanate, ceftriaxone, azithromycin, clarithromycin, levofloxacin, moxifloxacin, ciprofloxacin, doxycycline) during the enrollment window within 3 days of CAP claim	890 784	100.0
Exclusion Criteria	No.	%
Patients without continuous enrollment in medical and pharmacy benefits for at least 12 months before the index date	676 642	76.0
Patients without continuous enrollment in medical and pharmacy benefits for a minimum of 30 days after the index date	654 105	73.4
Hospitalization for any reason within 2 days of index prescription claim	618 326	69.4
Patients with prescription fills for any antibiotic in the 30 days before diagnosis of CAP	508 384	57.1
Patients with medical claim containing a primary diagnosis of CAP in the 30 days before the first outpatient medical claim in the enrollment window	498 408	56.0
Patients with HMO enrollment	424 577	47.7
Patients on combination antibiotics	413 801	46.5
Sample size after applying all pre- and postindex eligibility requirements	413 801	46.5
Patients aged ≥18 years (final sample size)	257 165

Of this population, 257 165 were aged ≥18 years and served as the primary focus of subsequent analysis.

Abbreviations: CAP, community-acquired pneumonia; HMO, Healthcare Maintenance Organization.

^aSample size = 413 801 after all inclusion/exclusion criteria were met.