Research Article

Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

Table 1

Study population and characteristics of index colonoscopy.

Clinical setting of index colonoscopyEntire population
Teaching hospitalCommunity hospitalNonhospital facility

Number of patients35,988 (10.8%)181,039 (54.1%)117,636 (35.1%)334,663

Patient factors value among strata
Age
 50–54 years8,722 (24.2%)45,437 (25.1%)39,953 (34.0%)<0.000194,112 (28.1%)
 55–59 years7,423 (20.6%)37,220 (20.6%)26,255 (22.3%)70,898 (21.2%)
 60–64 years7,039 (19.6%)33,708 (18.6%)21,102 (17.9%)61,849 (18.5%)
 65–69 years6,003 (16.7%)30,313 (16.7%)16,406 (14.0%)52,722 (15.8%)
 70–74 years4,212 (11.7%)21,050 (11.6%)9,520 (8.1%)34,782 (10.4%)
 75–79 years2,589 (7.2%)13,311 (7.4%)4,400 (3.7%)20,300 (6.1%)

Female19,984 (55.5%)95,409 (52.7%)59,675 (50.7%)<0.0001175,068 (52.3%)
Male16,004 (44.5%)85,630 (47.3%)57,961 (49.3%)159,595 (47.7%)

Residence
 Income quintile 15,368 (14.9%)20,683 (11.42%)15,596 (13.3%)<0.000141,647 (12.4%)
 Income quintile 25,986 (16.6%)25,722 (14.2%)19,832 (16.9%)51,400 (15.4%)
 Income quintile 36,000 (16.7%)29,277 (16.2%)22,191 (18.9%)57,468 (17.2%)
 Income quintile 46,838 (19.0%)34,405 (19.0%)25,812 (21.9%)67,055 (20.0%)
 Income quintile 59,121 (25.3%)35,006 (19.3%)29,915 (25.4%)74,042 (22.1%)
 Rural2,675 (7.4%)35,946 (19.9%)4,290 (3.7%)42,911 (12.8%)

ADG score
 Mean (SD)4.91 (3.01)4.88 (2.82)4.24 (2.63)<0.00014.72 (2.79)
 Median (IQR)4 (3, 7)4 (3, 7)4 (2, 6)4 (3–6)

Colonoscopy factors
Complete34,844 (96.8%)177,338 (98.0%)115,772 (98.4%)<0.0001327,954 (98.0%)
Incomplete1,144 (3.2%)3,701 (2.0%)1,864 (1.6%)6,709 (2.0%)

Open access21,584 (60.0%)58,834 (32.5%)85,148 (72.4%)<0.0001165,566 (49.5%)
Not open access14,404 (40.0%)122,205 (67.5%)32,488 (27.6%)169,097 (50.5%)

Most complex procedure at index colonoscopy
  “Removal of large polyp or obstructing lesion”228 (0.6%)1,284 (0.7%)609 (0.5%)<0.00012,121 (0.6%)
 Standard polypectomy6,060 (16.8%)32,412 (17.9%)18,875 (16.1%)57,347 (17.1%)
 Biopsy6,368 (17.7%)21,195 (11.7%)8,965 (7.6%)36,528 (10.9%)
 None of the above or none23,332 (64.8%)126,148 (69.7%)89,187 (75.8%)238,667 (71.3%)

Endoscopist
Female68 (24.3%)145 (19.5%)123 (17.3%)0.05215 (20.9%)
Male212 (75.7%)597 (80.5%)579 (81.8%)810 (78.6%)

Endoscopist specialty
 Gastroenterology110 (39.3%)159 (21.4%)196 (27.5%)<0.0001250 (24.4%)
 General surgery117 (41.2%)420 (56.6%)351 (49.3%)512 (49.9%)
 Internal medicine43 (15.4%)76 (10.2%)108 (15.2%)130 (12.7%)
 Other10 (3.6%)87 (11.7%)57 (8.0%)133 (13.0%)

Endoscopist prior year practice factors
Prior year colonoscopy volumeMean: 406.6533.6Mean: 554.9<0.0001Mean 468.8
(SD: 439.0)(SD 419.7)(SD: 433.2)(SD 407.2)
Median 305Median 455Median 492Median 384
(IQR 94–559)(IQR 214–755)(IQR 224–755)(IQR 150–661)

Prior year volume “removal of large polyp or obstructing lesion”Mean: 3.8Mean: 3.9Mean: 4.5<0.0001Mean 3.5
(SD: 11.8)(SD: 11.1)(SD: 12.3)(SD 10.7)
Median 0Median: 0Median: 1Median 0
(IQR 0–3)IQR (0–4)(IQR 0–4)(IQR 0–3)

Prior year standard polypectomy volumeMean: 132.5Mean: 188.8Mean: 195.5<0.0001Mean 163.4
(SD: 179)(SD: 185.6)(SD: 199.9)(SD 182.7)
Median 85Median: 136Median: 142Median 110
(IQR 25–168)(IQR 62–260)(IQR 61–275)(IQR 38–232)

Prior year cecal intubation rateMean 0.92Mean 0.95Mean 0.95<0.0001Mean 0.94
(SD 0.09)(SD 0.07)(SD 0.09)(SD 0.09)
Median 0.94Median 0.96Median 0.96Median 0.96
(IQR 0.91–0.97)(IQR 0.94–0.98)(IQR 0.93–0.98)(IQR 0.93–0.98)

The majority of endoscopists performed colonoscopy at two or more settings.)