Table 1. Characteristics of study participants and estimated ORs and 95% CIs for UCC associated with risk factors.
| Matching variables | Controls N=439 | Cases N=439 | |
|---|---|---|---|
| Age at blood draw | Median=65.6 | Median=65.3 | |
| IQR=60.3–69.2 | IQR=60.2–69.6 | ||
| DNA source | |||
| Dried blood spot | 178 (41%) | 178 (41%) | |
| PBMC | 98 (22%) | 98 (22%) | |
| Buffy coat | 163 (37%) | 163 (37%) | |
| Sex | |||
| Male | 335 (76%) | 335 (76%) | |
| Country of birth | |||
| Aus/NZ/UK | 302 (69%) | 302 (69%) | |
| Italy | 79 (18%) | 79 (18%) | |
| Greece | 58 (13%) | 58 (13%) | |
| Other risk factors (at blood draw) | Controls N=439 | Cases N=439 | Adjusted ORa (95% CI) |
| Smoking | |||
| Never | 185 (42%) | 128 (29%) | Ref. |
| Current | 56 (13%) | 78 (18%) | 2.1 (1.3–3.3) |
| Former | 198 (45%) | 233 (53%) | 1.9 (1.4–2.7) |
| Alcohol consumptionb | |||
| None | 102 (23%) | 112 (26%) | Ref. |
| Low | 273 (62%) | 253 (58%) | 0.8 (0.5–1.1) |
| Moderate | 39 (9%) | 41 (9%) | 0.9 (0.5–1.5) |
| High | 25 (6%) | 33 (7%) | 1.0 (0.5–2.8) |
| BMI | |||
| <25 kg m−2 | 135 (30%) | 113 (26%) | Ref. |
| 25–30 kg m−2 | 216 (51%) | 224 (51%) | 1.1 (0.8–1.5) |
| ⩾30 kg m−2 | 88 (19%) | 102 (23%) | 1.2 (0.8–1.8) |
| SES indicatorc | |||
| Quintile 1 | 61 (14%) | 78 (18%) | Ref. |
| Quintile 2 | 96 (22%) | 96 (22%) | 0.9 (0.6–1.3) |
| Quintile 3 | 83 (19%) | 84 (19%) | 0.9 (0.5–1.3) |
| Quintile 4 | 92 (21%) | 82 (19%) | 0.8 (0.5–1.2) |
| Quintile 5 | 107 (24%) | 99 (23%) | 0.8 (0.5–1.3) |
| Folate intaked | |||
| Quintile 1 | 85 (19%) | 89 (20%) | Ref. |
| Quintile 2 | 85 (19%) | 91 (21%) | 1.2 (0.7–1.9) |
| Quintile 3 | 88 (20%) | 89 (20%) | 1.0 (0.6–1.6) |
| Quintile 4 | 84 (19%) | 91 (21%) | 1.2 (0.7–2.0) |
| Quintile 5 | 97 (22%) | 79 (18%) | 0.9 (0.5–1.6) |
| Vitamin B12d | |||
| Quintile 1 | 89 (20%) | 85 (19%) | Ref. |
| Quintile 2 | 84 (19%) | 92 (21%) | 1.1 (0.7–1.7) |
| Quintile 3 | 93 (21%) | 84 (19%) | 1.0 (0.6–1.6) |
| Quintile 4 | 78 (18%) | 97 (22%) | 1.4 (0.9–2.2) |
| Quintile 5 | 95 (22%) | 81 (18%) | 0.9 (0.6–1.5) |
| Clinical variables | Cases N=439 | Adjusted ORa (95% CI) | |
| Time between blood draw and diagnosis | Median=6.3 | Per year increase | |
| IQR=3.5–10.4 | 1.1 (0.9–1.3) | ||
| Age at diagnosis | Median=73.3 | ||
| IQR=67.1–77.9 | |||
| Tumour invasiveness | |||
| Invasive | 193 (44%) | ||
| Superficial | 246 (56%) | ||
| Tumour grade | |||
| Grade 1 | 108 (25%) | ||
| Grade 2 | 104 (24%) | ||
| Grade 3 | 147 (33%) | ||
| Unknown | 80 (18%) |
Abbreviations: Aus=Australia; BMI=body mass index; CI=confidence interval; IQR=interquartile range; NZ=New Zealand; OR=odds ratio; PBMC=peripheral blood mononuclear cell; Ref=reference; SES=socioeconomic status; UCC=urothelial cell carcinoma.
Mutually adjusted ORs using a conditional logistic regression model with matching on age, DNA source, sex, and country of birth, and included covariates: smoking, alcohol consumption, body mass index, socioeconomic status, folate and vitamin B12 intakes, and time between blood draw and diagnosis.
Alcohol consumption was defined according to the Australian National Health and Medical Research Council categories as follows: None=0 g per day (males and females); Low=1–39 g per day (males) and 1–19 g per day (females); Moderate=40–59 g per day (males) and 20–39 g per day (females); High=60+ g per day (males) and 40+ g per day (females).
Index of Relative Socioeconomic Disadvantage score from the Socio Economic Indexes for Area defined by the Australian Bureau of Statistics, divided into quintiles (quintile 1 is the most disadvantaged).
Folate and vitamin intakes were computed using the Melbourne Collaborative Cohort Study (MCCS) 121-item Food Frequency Questionnaire.