Suitability of administrative claims databases for bariatric surgery research – is the glass half-full or half-empty?

Table 3 Validation results for the BMI categorization algorithm in the 6-month preoperative (Cohort 2) and 1-year postoperative periods (Cohort 3)

BMI categories, kg/m²	ICD-9-CM or ICD-10-CM Diagnoses	Last preoperative BMI^a					Last postoperative BMI^b
BMI categories, kg/m²	ICD-9-CM or ICD-10-CM Diagnoses	Sensitivity	Specificity	PPV	NPV	Kappa (95% CI)	Sensitivity	Specificity	PPV	NPV	Kappa (95% CI)
≤19.9	V85.0, Z68.1	100	100	80	100	0.78 (0.76, 0.79)	100	100	100	100	0.84 (0.80,0.87)
20.0–24.9	V85.1, Z68.20-Z68.24	60	100	100	100		75	100	100	100
25.0–29.9	V85.21-V85.25, Z68.25-Z68.29	70	100	100	100		> 82^c	> 98^c	> 82^c	98
30.0–34.9	V85.30-V85.34, Z68.30-Z68.34	30	100	> 62^c	99		84	> 97^c	> 93^c	93
35.0–39.9	V85.35-V85.39, Z68.35-Z68.39	64	97	81	93		84	94	81	95
40.0–44.9	V85.41, Z68.41	76	87	71	90		76	93	68	95
45.0–49.9	V85.42, Z68.42	71	90	65	92		72	97	73	97
50.0–59.9	V85.43, Z68.43	79	93	76	94		> 65^c	97	61	> 98^c
60.0–69.9	V85.44, Z68.44	70	98	67	98		100	99	17	100
≥70.0	V85.45, Z68.45	53	100	63	99		--^d	100	0	100
≤29.9	V85.0, V85.1, V85.21-V85.25, Z68.1, Z68.20-Z68.29	87	100	100	100	0.77 (0.76, 0.79)	> 84^c	> 98^c	> 84^c	98	0.82 (0.78, 0.87)
30.0–39.9	V85.30-V85.39, Z68.30-Z68.39	67	98	90	93		89	93	94	87
40.0–49.9	V85.41, V85.42, Z68.41, Z68.42	89	81	82	88		86	93	80	95
50.0–59.9	V85.43, Z68.43	79	93	76	94		> 65^c	97	61	> 98^c
≥60.0	V85.44, V85.45, Z68.44, Z68.45	75	98	74	98		100	99	14	100
≤19.9	V85.0, Z68.1	100	100	80	100	0.94 (0.89, 0.99)	100	100	100	100	0.90 (0.84, 0.96)
20.0–24.9	V85.1, Z68.20-Z68.24	60	100	100	100		75	100	100	100
25.0–29.9	V85.21-V85.25, Z68.25-Z68.29	70	100	100	100		> 82^c	> 98^c	> 82^c	98
≥30.0	V85.30-V85.39, V85.41-V85.45, Z68.30-Z68.39, Z68.41-Z68.45	100	87	100	100		> 98^c	> 81^c	98	> 81^c

Abbreviations: BMI body mass index, ICD international classification of diseases, PPV positive predictive value, NPV negative predictive value, CI confidence interval
^a The last available weight-related diagnosis code in claims in the 6-month preoperative period was compared with the last available BMI measurement in the electronic health records (EHR) during the same period in Cohort 2 patients
^b The last available weight-related diagnosis code in claims in the 1-year postoperative period was compared with the last available BMI measurement in the EHR during the same period in Cohort 3 patients
^c Cells with 10 or fewer patients have been suppressed to maintain the de-identification nature of the database
^d Sensitivity was not calculated because no patients had relevant BMI measurement at this level in the EHR

ISSN: 1471-2288