Validation of 5 key colonoscopy-related data elements from Ontario health administrative databases compared to the clinical record: a cross-sectional study

Jill Tinmouth; Rinku Sutradhar; Ning Liu; Nancy N. Baxter; Lawrence Paszat; Linda Rabeneck

doi:10.9778/cmajo.20180013

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Figure 2:
Flow chart showing sampling of facilities and procedures.
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Figure 1:
Weighted sensitivity and specificity of 14 administrative data definitions using Ontario Health Insurance Plan (OHIP) codes of colonoscopy case compared to the reference standard of colonoscopy intended or performed according to the medical record. Note: CI = confidence interval.
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Figure 3:
Receiver operating curve of the 14 definitions for colonoscopy case. Upper left point of curve corresponds to Ontario Health Insurance Plan (OHIP) definition 6: OHIP codes Z555A + E741A ± other E codes.
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Figure 4:
Sensitivity and specificity of nonhospital setting, colonoscopy completeness, anesthesiologist assistance and polypectomy compared to reference standards. Note: CI = confidence interval, CIHI = Canadian Institute for Health Information, OHIP = Ontario Health Insurance Plan.

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Table 1:

Description of the cohorts, administrative data definitions and reference standards for 5 colonoscopy data elements

Element	Cohort description, size	Administrative data definition	Reference standard
Colonoscopy case	All successfully abstracted charts, n = 1845	OHIP codes: Z555A alone or in combination with any of: E740A, E741A, E747A or E705A 14 of the most clinically plausible combinations were evaluated (see Figure 1 for the specific codes included in each definition)	Colonoscopy was performed, or there was intent to perform colonoscopy according to endoscopist’s procedure note^*
Nonhospital clinic	Charts in which colonoscopy was intended or performed, n = 1282	OHIP code E649A billed on date of colonoscopy No record in CIHI database overlapping with date of colonoscopy according to OHIP database (i.e., no record of procedure’s being done in hospital) OHIP code E649A and no overlapping record in CIHI database	Presence of endoscopist’s procedure note in nonhospital facility chart
Anesthesiologist assistance	Charts in which colonoscopy was intended or performed, n = 1282	OHIP codes for anesthesia (003C or procedure code with “C” suffix [see supplementary tables, Appendix 1, available at www.cmajopen.ca/content/6/3/E330/suppl/DC1]) billed on date as colonoscopy in same patient	Presence of anesthesiologist record in chart regardless of type of sedating agent Use of propofol as sedating agent according to anesthesiologist’s record^†
Colonoscopy completeness^‡	Charts in which procedure billed with colonoscopy codes, and colonoscopy or flexible sigmoidoscopy was intended,^§ n = 1477 (administrative data definition 1), n = 1016 (administrative data definition 2)	OHIP code E747A (to cecum) or E705A (to terminal ileum) billed among colonoscopy procedures defined using most sensitive definition (Z555A ± other E codes) OHIP code E747A or E705A billed among colonoscopy procedures defined using most accurate definition (Z555A + E741 ± other E codes)	Colonoscopy “intended” and “complete” according to endoscopist’s procedure note
Polypectomy^¶	Charts in which colonoscopy was intended or performed,^** n = 1256 (reference standard 1), n = 1252 (reference standard 2)	OHIP code Z571A alone OHIP code Z571A, Z570A or E685A OHIP code Z571A, Z570A, E685A or E717A	Polyp visualized or polypectomy described according to endoscopist’s procedure note Adenoma, advanced adenoma or sessile serrated polyp according to pathologist’s report^††

Note: CIHI = Canadian Institute for Health Information, OHIP = Ontario Health Insurance Plan.
↵* Completed by the endoscopist; includes a description of the procedure, including findings.
↵† Completed by the anesthesiologist; record of anesthetic administered during the procedure.
↵‡ Procedures intended as flexible sigmoidoscopy for which E747A or E705A was billed were classified as false-positive. Procedures intended as flexible sigmoidoscopy for which E747A and E705A were not billed were classified as false-negative.
↵§ Excluding those with prior total colectomy or right hemicolectomy.
↵¶ Because the histologic findings of the polyp are not available in administrative databases, we could not define adenoma using these data.
↵** Excluding those with missing data for reference standard.
↵†† Report on the histologic findings of specimens, such as polyps, obtained at colonoscopy.

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Table 2:

Patient and procedure characteristics for all successfully abstracted charts and for charts in which colonoscopy was intended or performed

Characteristic	No. (%) of charts^*
Characteristic	All abstracted charts n = 1845	Colonoscopy intended or performed n = 1282
Age group, yr
< 50	469 (25.4)	251 (19.6)
50–59	517 (28.0)	395 (30.8)
60–69	430 (23.3)	327 (25.5)
70–74	174 (9.4)	134 (10.4)
> 74	255 (13.8)	175 (13.6)
Sex
Female	986 (53.4)	709 (55.3)
Male	859 (46.6)	573 (44.7)
Procedure(s) performed^†
Colonoscopy only	1143 (62.0)	1125 (87.8)
Gastroscopy only	45 (2.4) ≤ 5
Flexible sigmoidoscopy only	432 (23.4) ≤ 5
Colonoscopy + gastroscopy	200 (10.8)	151 (11.8)
Flexible sigmoidoscopy + gastroscopy	12 (0.6)	≤ 5
Colonoscopy + other procedure	≤ 5	≤ 5
Flexible sigmoidoscopy + other procedure	≤ 5	0 (0)
Other procedure only	6 (0.3)	0 (0)
Median neighbourhood income quintile^‡
1 (lowest)	300 (16.3)	205 (16.0)
2	331 (17.9)	225 (17.6)
3	337 (18.3)	233 (18.2)
4	393 (21.3)	265 (20.7)
5 (highest)	474 (25.7)	348 (27.1)
Missing	10 (0.5)	6 (0.5)
Setting
Nonhospital clinic	284 (15.4)	216 (16.8)
Hospital	1561 (84.6)	1066 (83.2)

↵* To ensure confidentiality, counts of 5 or less are suppressed.
↵† Based on findings at chart abstraction.
↵‡ Median annual neighborhood household income at the level of enumeration area, obtained from Statistics Canada, was linked to patient postal code.

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Table 3:

Positive predictive values of OHIP definition of colonoscopy, nonhospital setting, colonoscopy completeness, anesthesiologist assistance and polypectomy compared to reference standards

OHIP definition	PPV (95% CI)
Colonoscopy case
1. Z555A ± other E codes	96.4 (95.2–97.6)
2. Z555A + E740A ± other E codes	97.7 (96.6–98.8)
3. Z555A + E740A + E741A ± other E codes	99.1 (98.0–100)
4. Z555A + E740A + E741A + E747A ± other E codes	99.1 (98.1–100)
5. Z555A + E740A + E741A + E747A + E705A	98.3 (96.0–100)
6. Z555A + E741A ± other E codes	99.1 (98.1–100)
7. Z555A + E747A ± other E codes	99.2 (98.1–100)
8. Z555A + E705A ± other E codes	98.3 (96.0–100)
9. Z555A + E740A + E747A ± other E codes	99.1 (98.1–100)
10. Z555A + E740A + E705A ± other E codes	98.3 (96.0–100)
11. Z555A + E741A + E747A ± other E codes	99.2 (98.1–100)
12. Z555A + E741A + E705A ± other E codes	98.3 (96.0–100)
13. Z555A + E747A + E705A ± other E codes	98.3 (96.0–100)
14. Z555A + 1 or more of E740A, E741A, E747A or E705A	97.7 (96.6–98.8)
Nonhospital setting
1. E649A billed on date of colonoscopy	100 (100–100)
2. No record in CIHI database overlapping with date of colonoscopy according to OHIP database	100 (100–100)
3. E649A and no overlapping record in CIHI database	100 (100–100)
Colonoscopy completeness, defined using most sensitive colonoscopy definition
1. Weighted analysis results	99.0 (98.3–99.7)
2. Unweighted analysis results	99.0 (98.3–99.7)
Colonoscopy completeness, defined using most accurate colonoscopy definition
1. Weighted analysis results	99.0 (98.3–99.7)
2. Unweighted analysis results	99.0 (98.3–99.7)
Anesthesiologist assistance
1. v. “anesthesiologist’s record”	83.8 (71.5–96.0)
2. v. “use of propofol”	77.2 (64.3–90.1)
Polypectomy
v. “polyp seen or removed”
1. Z571A alone	99.0 (97.7–100)
2. Z571A, Z570A or E685A	98.7 (97.3–100)
3. Z571A, Z570A, E717A or E685A	79.2 (74.3–84.2)
v. “histology”
1. Z571A alone	68.1 (62.2–74.1)
2. Z571A, Z570A or E685A	64.1 (58.1–70.2)
3. Z571A, Z570A, E717A or E685A	49.7 (44.4–55.0)

Note: CI = confidence interval, CIHI = Canadian Institute for Health Information, OHIP = Ontario Health Insurance Plan, PPV = positive predictive value.