Volume 29, Number 9—September 2023
Research
Validation of Claims-Based Algorithm for Lyme Disease, Massachusetts, USA
, Sheryl A. Kluberg, Sarah J. Willis, Susan Forrow, Bradford D. Gessner, Cameron T. Nutt, Alejandro Cane, Nathan Petrou, Meera Sury, Chanu Rhee, Luis Jodar, Aaron Mendelsohn, Emma R. Hoffman, Robert Jin, John Aucott, Sarah J. Pugh, and James H. Stark
Table 3
Numbers of reviewed charts and positive predictive values according to case definitions and other factors during January 2015–June 2019 in study of validation of claims-based algorithm for Lyme disease, Massachusetts, USA*
| Factors | Reviewed charts | Confirmed | Probable | Suspected | Not LD | % PPV (95% CI)† | % PPV (95% CI)‡ |
|---|---|---|---|---|---|---|---|
| Overall |
128 |
70 |
15 |
35 |
8 |
93.8 (88.1–97.3) |
66.4 (57.5–74.5) |
| Age group, y | |||||||
| Pediatric, <18 | 25 (19.5%) | 19 | 3 | 3 | 0 | 100 (86.3–100) | 88 (68.8–97.5) |
| Adults, >18 |
103 (80.5%) |
51 |
12 |
32 |
8 |
92.2 (85.3–96.6) |
61.2 (51.1–70.6) |
| ICD era§ | |||||||
| ICD-9-CM | 25 (19.5%) | 16 | 3 | 4 | 2 | 92.0 (74.0–99.0) | 76.0 (54.9–90.6) |
| ICD-10-CM |
103 (80.5%) |
54 |
12 |
31 |
6 |
94.2 (87.8–97.8) |
64.1 (54.0–73.3) |
| Healthcare facility type | |||||||
| Primary care | 95 (74.2%) | 51 | 14 | 26 | 4 | 95.8 (89.6–98.8) | 68.4 (58.1–77.6) |
| Urgent care | 17 (13.3%) | 12 | 1 | 4 | 0 | 100 (80.5–100) | 76.5 (50.1–93.2) |
| Other¶ |
16 (12.5%) |
7 |
0 |
5 |
4 |
75.0 (47.6–92.7) |
31.3 (11.0–58.7) |
| Laboratory tests# | 68 (53.1%) | 27 | 15 | 21 | 5 | 92.7 (83.7–97.6) | 61.8 (49.2–73.3) |
*Values are no. (%) except as indicated. Lyme disease case definitions are confirmed, probable, suspected, and not Lyme disease. ICD, International Classification of Diseases; ICD-9, ICD, 9th Revision, Clinical Modification; ICD-10, ICD, 10th Revision, Clinical Modification; LD, Lyme disease; PPV, positive predictive value. †Confirmed, probable, or suspected cases. ‡Confirmed or probable cases only. §Case dates were January 2015–September 2015 for ICD-9 and October 2015–June 2019 for ICD-10. ¶Includes specialist practice (n = 5), emergency department (n = 3), telephone encounter (n = 3), and unknown facility type (n = 5). #Laboratory testing performed (regardless of result).