Identifying pediatric diabetes cases from health administrative data: a population-based validation study in Quebec, Canada

Figures & data

Figure 1 Identification of the reference standard population for algorithm development.

Notes: *Prediabetes, transient diabetes, drug-induced diabetes. **For a given year, a resident of Montréal/Laval is a child who lived in Montreal or Laval during the 365 days of the year and had a valid health insurance card at least half of the year.

Table 1 Accuracy of different diabetes algorithms in a cohort of children and adolescents ages 1–15 years living in Montreal or Laval, 2002–2011 (stage 1)

Algorithm^a	True positive (N)	False negative (N)	False positive (N)	True negative (N)	Sensitivity (%) (95% CI)	Specificity (%) (95% CI)	PPV (%)(95% CI)	NPV (%)(95% CI)
Two claims or any hospitalization in 2 years	860	29	174	429,192	96.7 (95.4–97.7)	100 (100–100)	83.2 (80.8–85.3)	100 (100–100)
Two claims or any hospitalization in 2 years + (CCDSS)	869	20	226	429,140	97.8 (96.6–98.5)	99.9 (99.9–100.0)	79.4 (76.9–81.7)	100 (100–100)
One claim	869	20	1097	428,269	97.8 (96.6–98.5)	99.7 (99.7–99.8)	44.2 (42.0–46.4)	100 (100–100)
Two claims in 1 year	840	49	143	429,223	94.5 (92.8–95.8)	100 (100–100)	85.5 (83.1–87.5)	100 (100–100)
Three claims in 1 year	799	90	65	429,301	89.9 (87.7–91.7)	100 (100–100)	92.5 (90.5–94.1)	100 (100–100)
Four claims in 1 year	748	141	40	429,326	84.1 (81.6–86.4)	100 (100–100)	94.9 (93.2–96.3)	100 (100–100)
Five claims in 1 year	638	251	17	429,349	71.8 (68.7–74.6)	100 (100–100)	97.4 (95.9–98.4)	99.9 (99.9–99.9)
Two claims in 2 years	849	40	165	429,201	95.5 (93.9–96.7)	100 (100–100)	83.7 (81.3–85.9)	100 (100–100)
Three claims in 2 years	827	62	86	429,280	93.0 (91.2–94.5)	100 (100–100)	90.6 (88.5–92.3)	100 (100–100)
Four claims in 2 years	804	85	59	429,307	90.4 (88.3–92.2)	100 (100–100)	93.2 (91.3–94.7)	100 (100–100)
Five claims in 2 years	778	111	42	429,324	87.5 (85.2–89.5)	100 (100–100)	94.9 (93.1–96.2)	100 (100–100)
One hospitalization	431	458	27	429,339	48.5 (45.2–51.8)	100 (100–100)	94.1 (91.6–95.9)	99.9 (99.9–99.9)
One claim or any hospitalization	872	17	1099	428,267	98.1 (97.0–98.8)	99.7 (99.7–99.8)	44.2 (42.1–46.4)	100 (100–100)
Two claims or any hospitalization in 1 year	853	36	152	429,214	96.0 (94.4–97.1)	100 (100–100)	84.9 (82.5–87.0)	100 (100–100)
Three claims or any hospitalization in 1 year	828	61	80	429,286	93.1 (91.3–94.6)	100 (100–100)	91.2 (89.2–92.9)	100 (100–100)
Four claims or any hospitalization in 1 year	811	78	56	429,310	91.2 (89.2–92.9)	100 (100–100)	93.5 (91.7–95.0)	100 (100–100)
Five claims or any hospitalization in 1 year	742	147	38	429,328	83.5 (80.9–85.8)	100 (100–100)	95.1 (93.4–96.4)	100 (100–100)
Three claims or any hospitalization in 2 years	848	41	98	429,268	95.4 (93.8–96.6)	100 (100–100)	89.6 (87.5–91.4)	100 (100–100)
Four claims or any hospitalization in 2 years	837	52	74	429,292	94.2 (92.4–95.5)	100 (100–100)	91.9 (89.9–93.5)	100 (100–100)
Five claims or any hospitalization in 2 years	825	64	59	429,307	92.8 (90.9–94.3)	100 (100–100)	93.3 (91.5–94.8)	100 (100–100)

Note: ^aAll claims separated by 30 days except those indicated by +.

Abbreviations: PPV, Positive Predictive Value; NPV, Negative Predictive Value.

Table 2 Validation of selected algorithms in a cohort of children and adolescents ages 1–17 years living in Quebec City or Sherbrooke, 2002–2011 (stage 2)

Algorithm^a	True positive (N)	False negative (N)	Sensitivity (%) (95% CI)	False positive (N)	True negative (N)	Specificity (%) (95% CI)	LR−	LR+
Two claims or any hospitalization in 2 years	341	4	98.8 (97.1–99.5)	0	366	100 (99.0–100.0)	0.012	N/A
Two claims or any hospitalization in 2 years + (CCDSS)	341	4	98.8 (97.1–99.5)	0	366	100 (99.0–100.0)	0.012	N/A
Four claims in 2 years	330	15	95.7 (93.0–97.3)	0	366	100 (99.0–100.0)	0.043	N/A
Four claims or any hospitalization in 1 year	321	24	93.0 (89.9–95.3)	0	366	100 (99.0–100.0)	0.070	N/A

Note: ^aAll claims separated by 30 days except those indicated by +.

Abbreviations: LR, likelihood ratio.

Table 3 Validation of selected case definitions in a cohort of children and adolescents ages 1–15 years living in Quebec City or Sherbrooke, 2002–2011 (stage 2)

Algorithm^a	True positive (N)	False negative (N)	Sensitivity (%) (95% CI)	False positive (N)	True negative (N)	Specificity (%) (95% CI)	LR−	LR+
Two claims or any hospitalization in 2 years	292	3	99.0 (97.1–99.7)	0	365	100 (99.0–100.0)	0.010	N/A
Two claims or any hospitalization in 2 years +	292	3	99.0 (97.1–99.7)	0	365	100 (99.0–100.0)	0.010	N/A
Four claims in 2 years	284	11	96.3 (93.4–97.9)	0	365	100 (99.0–100.0)	0.037	N/A
Four claims or any hospitalization in 1 year	277	18	93.9 (90.6–96.1)	0	365	100 (99.0–100.0)	0.061	N/A

Note: ^aAll claims separated by 30 days except those indicated by +.

Abbreviations: LR, likelihood ratio.

Table 4 Diagnostic accuracy of selected algorithms by diabetes type in a cohort of children and adolescents ages 1–15 years living in Montreal or Laval, 2002–2011 (Types 1 and 2)

	Type 1 diabetes			Type 2 diabetes
Algorithms^a	True positive (N)	False negative (N)	Sensitivity (95% CI)	True positive (N)	False negative (N)	Sensitivity (95% CI)
Two claims or any hospitalization in 2 years	813	20	97.6 (96.3–98.4)	31	8	79.5 (64.5–89.2)
Two claims or any hospitalization in 2 years +	821	12	98.6 (97.5–99.2)	32	7	82.1 (67.3–91.0)
Four claims in 2 years	770	63	92.4 (90.4–94.0)	23	16	59.0 (43.4–72.9)
Four claims or any hospitalization in 1 year	775	58	93.0 (91.1–94.6)	25	14	64.1 (48.4–77.3)

Note: ^aAll claims separated by 30 days except those indicated by +.

Table 5 Diagnostic accuracy of selected algorithms by age-group in a cohort of children and adolescents ages 1–15 years living in Montreal or Laval in 2011

Algorithm^a	Age group in 2011	True positive (N)	False negative (N)	False positive (N)	True negative (N)	Sensitivity (%) (95% CI)	Specificity (%) (95% CI)	PPV (%)(95% CI)	Prevalence (%) (95% CI)
Two claims or any hospitalization in 2 years	1–4 years	34	0	8	63,168	100.0 (89.8–100.0)	100.0 (100.0–100.0)	81.0 (66.7–90.0)	0.07 (0.05–0.09)
	5–10 years	148	8	20	108,701	94.9 (90.2–97.4)	100.0 (100.0–100.0)	88.1 (82.3–92.2)	0.15 (0.13–0.18)
	11–15 years	246	8	45	94,300	96.9 (93.9–98.4)	100.0 (99.9–100.0)	84.5 (79.9–88.2)	0.31 (0.27–0.34)
Two claims or any hospitalization in 2 years +	1–4 years	34	0	13	63,163	100.0 (89.8–100.0)	100.0 (100.0–100.0)	72.3 (58.2–83.1)	0.07 (0.06–0.10)
	5–10 years	151	5	32	108,689	96.8 (92.7–98.6)	100.0 (100.0–100.0)	82.5 (76.4–87.3)	0.17 (0.15–0.19)
	11–15 years	249	5	59	94,286	98.0 (95.5–99.2)	99.9 (99.9–100.0)	80.8 (76.1–84.8)	0.33 (0.29–0.36)
Four claims in 2 years	1–4 years	31	3	2	63,174	91.2 (77.0–97.0)	100.0 (100.0–100.0)	93.9 (80.4–98.3)	0.05 (0.04–0.07)
	5–10 years	137	19	5	108,716	87.8 (81.8–92.1)	100.0 (100.0–100.0)	96.5 (92.0–98.5)	0.13 (0.11–0.15)
	11–15 years	226	28	16	94,329	89.0 (84.5–92.3)	100.0 (100.0–100.0)	93.4 (89.5–95.9)	0.26 (0.23–0.29)
Four claims or any hospitalization in 1 year	1–4 years	29	5	1	63,175	85.3 (69.9–93.6)	100.0 (100.0–100.0)	96.7 (83.3–99.4)	0.05 (0.03–0.07)
	5–10 years	137	19	4	108,717	87.8 (81.8–92.1)	100.0 (100.0–100.0)	97.2 (92.9–98.9)	0.13 (0.11–0.15)
	11–15 years	235	19	18	94,327	92.5 (88.6–95.2)	100.0 (100.0–100.0)	92.9 (89.0–95.5)	0.27 (0.24–0.30)

Note: ^aAll claims separated by 30 days except those indicated by +. −NPV was 100% across all Algorithms.

Abbreviations: PPV, positive predictive value; NPV, negative predictive value.