Article Figures & Tables
Figures
- Figure 1
Study design and follow-up for cohorts.
Tables
- Table 1: Characteristics of Ontario residents receiving bariatric surgery out of country and at an Ontario Bariatric Network centre of excellence, 2007-2012
Characteristic Group; no. (%) or mean ± SD Difference* (95% CI) Out of country
n = 4852OBN
n = 5179Age, yr 43.7 ± 10.3 44.9 ± 10.3 1.3 (0.9 to 1.6) Sex, female 3868 (80.5) 4258 (82.2) 1.7 (0.2 to 3.3) ACG comorbidity score p = 0.3 ≤ 2 123 (2.5) 72 (1.4) 3 2844 (58.6) 3077 (59.4) 4 1385 (28.5) 1524 (29.4) 5 500 (10.3) 506 (9.8) Rural residence† 898 (18.5) 818 (15.8) -2.7 (-4.2 to -1.2) Neighbourhood income quintile‡ p = 0.5 1 (lowest) 1096 (22.7) 1169 (22.6) 2 1109 (23.0) 1201 (23.3) 3 1005 (20.8) 1058 (20.5) 4 898 (18.6) 1008 (19.5) 5 (highest) 718 (14.9) 728 (14.1) Procedure: gastric bypass 4868 (99.9) 4738 (91.5) -8.4 (-7.6 to -9.2) Note: ACG = Johns Hopkins Adjusted Clinical Group, CI = confidence interval, NS = not significant, OBN = Ontario Bariatric Network, SD = standard deviation.
*Differences are reported as percentages with the exception of age, where mean difference is reported. For comparisons of characteristics with more than 2 categories, p values are reported.
†Rural residence was defined as residence in a community with a population less than 10 000.
‡Income quintile was determined by linking residential postal code to its corresponding dissemination area and then calculating the average income per person in the area. Areas were then ranked and divided into quintiles. The lowest income quintile was coded as 1 and the highest was coded as 5.
- Table 2: One-year postoperative health services use and mortality among patients who received bariatric surgery out of country and those who received it at an Ontario Bariatric Network centre, 2007-2012
Outcome Group; no. (%) or mean ± SD Difference* (95% CI), % Out of country
n = 4852OBN
n = 5179Any use of hospital services† 2513 (51.8) 2610 (50.4) -1.4 (-3.3 to 0.6) No. of days hospital services used by patients requiring ≥ 1 day 5.1 ± 12.4 4.7 ± 9.2 -0.5 (-0.1 to 1.1) Any emergency department visit 2311 (47.6) 2409 (46.5) -1.1 (-3.1 to 0.8) No. of emergency department visits among patients with ≥ 1 visit 2.4 ± 2.4 2.3 ± 2.2 -0.1 (-0.1 to -0.3) Any hospitalization 832 (17.2) 1014 (19.6) 2.4 (0.9 to 4.0) No. of days in hospital among patients requiring a hospital stay 8.7 ± 19.2 6.5 ± 12.5 -2.2 (-0.6 to -3.7) Any ICU stay 66 (1.4) 119 (2.3) 0.9 (0.4 to 1.5) No. of days in ICU among patients requiring an ICU stay 10.6 ± 12.3 4.7 ± 10.8 -5.9 (-2.3 to -9.5) Any ventilatory support 29 (0.6) 52 (0.5) -0.4 (-0.8 to -0.06) No. of ventilated days among patients requiring ventilation 11.1 ± 12.1 4.5 ± 8.2 -6.6 (-1.5 to -11.6) Any physician assessment 312 (6.4) 1761 (34.0) 27.6 (26.1 to 29.0) No. of physician assessments among patients with ≥ 1 assessment 1.6 ± 1.8 1.2 ± 0.6 -0.4 (-0.2 to -0.6) Reoperation 49 (1.01) 197 (3.8) 2.8 (2.2 to 3.4) No. of reoperations among patients with ≥ 1 reoperation 2.8 ± 1.8 1.4 ± 0.7 -1.4 (-0.9 to -1.9) 30-d mortality 4 (0.1) 7 (0.1) 0.05 (-0.2 to 0.08) 1-yr mortality 13 (0.3) 13 (0.3) 0.13 (-0.2 to 0.2) Note: CI = confidence interval, ICU = intensive care unit, OBN = Ontario Bariatric Network, SD = standard deviation.
*Differences are reported as percentages with the exception of mean differences.
†Hospital services = total no. of emergency department visits + days in hospital.
- Table 3: Unadjusted and adjusted rate ratios comparing 1-year postoperative health services use and mortality among patients in the Ontario Bariatric Network and those who received bariatric surgery out of country
Outcome Unadjusted rate ratio (95% CI) Adjusted* rate ratio (95% CI) Hospital services 0.88 (0.82 to 0.95) 0.90 (0.84 to 0.97) Emergency department visits 0.92 (0.86 to 0.98) 0.98 (0.92 to 1.05) Days in hospital 0.86 (0.73 to 1.00) 0.88 (0.75 to 1.03) Days in ICU 0.74 (0.45 to 1.25) 0.78 (0.45 to 1.35) Ventilatory support 0.68 (0.31 to 1.49) 0.67 (0.27 to 1.65) Physician assessments 4.06 (3.66 to 4.50) 4.10 (3.69 to 4.56) Reoperations 1.86 (1.37 to 2.53) 1.84 (1.34 to 2.53) Unadjusted OR (95% CI) Adjusted† OR (95% CI) 30-day mortality 1.64 (0.48 to 5.61) 1.61 (0.47 to 5.54) 1-year mortality 0.93 (0.43 to 2.02) 0.87 (0.40 to 1.89) Note: CI = confidence interval, ICU = intensive care unit, OR = odds ratio.
*Adjusted variables included age, sex, procedure, rurality, income quintile and comorbidity score.
†Adjusted variables included age and sex.
- Table 4: Rate ratios comparing 1-year postoperative health services use among patients who received bariatric surgery in Ontario hospitals outside the Ontario Bariatric Network after versus before 2010
Outcome Rate ratio* (95% CI) Hospital services 1.07 (0.59 to 1.93) Emergency department visits 0.70 (0.45 to 1.07) Days in hospital 1.04 (0.55 to 1.99) Days in ICU 0.13 (0.02 to 1.14) Ventilatory support 0.13 (0.01 to 26.3) Physician assessments 4.74 (2.36 to 9.5) Reoperations 0.81 (0.13 to 5.00) Note: CI = confidence interval, ICU = intensive care unit.
*Estimated using a negative binomial regression model adjusted for age, sex, household income quintile in neighbourhood of residence, rurality, type of bariatric surgery (gastric bypass v. other) and Johns Hopkins Adjusted Clinical Groups comorbidity score.
- Table 5: Unadjusted and adjusted rate ratios comparing 1-year postoperative health services use among patients in the Ontario Bariatric Network group and those who received surgery out of country, by patient characteristic
Variable Unadjusted rate ratio (95% CI) Adjusted rate ratio (95% CI) Surgery through the Ontario Bariatric Network 0.88 (0.82 to 0.95) 0.90 (0.84 to 0.97) Age 1.00 (0.99 to 1.00) 1.00 (0.99 to 1.00) Sex (male v. female) 1.09 (0.99 to 1.19) 1.08 (0.98 to 1.19) Procedure (gastric bypass v. other) 0.88 (0.74 to 1.06) 0.95 (0.79 to 1.15) Rurality (rural v. urban) 1.17 (1.07 to 1.29) 1.26 (1.14 to 1.40) ACG comorbidity score ≤ 2 1.00 (ref) 1.00 (ref) 3 1.46 (1.12 to 1.89) 2.06 (1.53 to 2.76) 4 2.29 (1.76 to 2.98) 3.29 (2.44 to 4.44) 5 4.42 (3.35 to 5.83) 5.67 (4.15 to 7.75) Income quintile 1 (lowest) 1.00 (ref) 1.00 (ref) 2 0.91 (0.82 to 1.00) 0.90 (0.81 to 1.00) 3 0.90 (0.81 to 1.00) 0.90 (0.81 to 1.01) 4 0.91 (0.81 to 1.01) 0.98 (0.88 to 1.10) 5 (highest) 0.81 (0.72 to 0.91) 0.79 (0.69 to 0.89) Note: ACG = Johns Hopkins Adjusted Clinical Group, CI = confidence interval,
ref = reference category.
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