Table 1.
Characteristics of Participants as Per Case and Control Status, MarketScan Commercial Database (2006–2015)
| Characteristics | Cases (N = 6001) | Controlsa (N = 52,104) |
|---|---|---|
| Age at the index dates (y), mean ± SD | 43.0 ± 5.8 | 42.8 ± 5.8 |
| Female, n (%) | 2922 (48.7) | 25,704 (49.3) |
| Geographical region, n (%) | ||
| South | 2631 (43.8) | 22,624 (43.4) |
| Northeast | 936 (15.6) | 8088 (15.5) |
| North Central | 1380 (23.0) | 11,744 (22.5) |
| West | 956 (15.9) | 8824 (16.9) |
| Unknown | 98 (1.6) | 824 (1.6) |
| Duration of insurance enrollment (y), median (IQR) | 3.5 (2.6–5.0) | 3.5 (2.6–4.9) |
| Prescription drug coverage, n (%) | 4951 (82.5) | 43,139 (82.8) |
| Full time employed, n (%) | 3075 (51.2) | 27,722 (53.2) |
| Residence, n (%) | ||
| Urban | 5005 (83.4) | 43,937 (84.3) |
| Rural | 902 (15.0) | 7370 (14.1) |
| Unknown | 94 (1.6) | 797 (1.5) |
| Health plan, n (%) | ||
| PPO | 3881 (64.7) | 32,672 (62.7) |
| HMO | 776 (12.9) | 7359 (14.1) |
| Other | 1344 (22.4) | 12,073 (23.2) |
| Inflammatory bowel diseaseb, n (%) | 287 (4.8) | 1372 (2.6) |
| Obesityb, n (%) | 428 (7.1) | 2972 (5.7) |
| Family history of gastrointestinal cancerb, n (%) | 75 (1.2) | 510 (1.0) |
| Fecal occult blood testb, n (%) | 452 (7.5) | 3078 (5.9) |
| Screening colonoscopyb, n (%) | 68 (1.1) | 1036 (2.0) |
| Other colonoscopyb, n (%) | 207 (3.4) | 914 (1.8) |
| Charlson comorbidity indexc, mean ± SD | 0.1 ± 0.5 | 0.06 ± 0.4 |
| Anatomical sited, n (%) | ||
| Colon | 3846 (64.1) | – |
| Proximal colon | 1156 (19.3) | – |
| Distal colon | 1115 (18.6) | – |
| Unspecified colon | 1575 (26.2) | – |
| Rectum | 2114 (35.2) | – |
| Metastatic statuse, n (%) | ||
| Non-metastatic | 4560 (76.0) | – |
| Metastatic | 1441 (24.0) | – |
HMO, health maintenance organization; IQR, interquartile range; PPO, preferred provider organization; SD, standard deviation.
Controls were matched based on age (18–24 years and every 5 years thereafter), sex (female, male), geographical region (Northeast, North Central, South, West, unknown), duration of insurance enrollment before index diagnosis (years), and prescription drug coverage (yes, no).
Between 91 days and 2 years before the index date.
The Charlson comorbidity index was calculated without diabetes and cancer.
A total of 41 cases with more than one anatomical site were excluded.
Metastatic colon cancer was determined using treatment encounters of liver or lung metastasis within 3 months after the index dates.