Table 2.
Attrition of patients using the inclusion/exclusion criteria and assignment to three treatment groups before 1:1:1 matching process.
| Criteria | Removed | Remaining |
|---|---|---|
| Number of patients MarketScan database (1/2005-6/2008) | NA | 49,042,666 |
| Have at least one COPD Study Drug between Jan 1, 2006 - Jun 30, 2007) | 48,879,492 | 163,174 |
| Omit patients with missing or zero quantity or days supply values on any COPD study prescription claim | 2,785 | 160,389 |
| Require at least one diagnosis for COPD (490.xx-492.xx, 494.xx, 496.xx) in any diagnosis field at any time in the data. | 44,560 | 115,829 |
| Omit patients with RX = 0 on any claims medical during the study period; this is MarketScan's indicator that the pharmacy claims were incomplete or unavailable. | 690 | 115,139 |
| Omit patients with a diagnosis of asthma (ICD-9-CM 493.xx), cystic fibrosis (277.0x), or respiratory tract cancer (160.x-164.x) at any time during the available data. | 51,149 | 63,990 |
| Require 12 months pre/12 months post index continuous eligibility | 19,871 | 44,119 |
| Include only patients aged 40 or older on index date | 205 | 43,914 |
| Have at least 30 days per quarter coverage for index prescription | 17,669 | 26,245 |
| Have at least one prescription for tiotropium, formoterol or salmeterol with treatment patterns that were in keeping with one of the three treatment groups (LABA or LAMA, LABA and LAMA or LABA, LAMA and ICS therapy) | 9,689 | 16,556 |
| Omit patients with missing PLANTYPs in CCAE enrollment data | 55 | 16,501 |
| Omit patients with negative dollar amounts in the NETPAY field. | 644 | 15,857 |
| TOTAL | 15,857 | |
| Treatment group distribution prior to propensity match: | n | % |
| LABA or LAMA group | 8,334 | 52.6 |
| LABA and LAMA group | 592 | 3.7 |
| LABA, LAMA, and ICS group | 6,931 | 43.7 |