Table 1.
Depression diagnoses and billing codes included in case definition
| ICD-9 Code | Diagnosis | Percentb |
|---|---|---|
| 296 | Episodic mood disorders | 0.0 |
| 296.2 And all subcodesa | Major depressive disorder, single episode | 12.5 |
| 296.3 And all subcodes | Major depressive disorder, recurrent episode | 26.0 |
| 296.5 And all subcodes | Bipolar affective disorder, depressed | 1.4 |
| 296.6 And all subcodes | Bipolar I disorder, mixed | 1.0 |
| 296.7 And all subcodes | Bipolar I disorder, unspecified | 0.9 |
| 296.8 And all subcodes | Other and unspecified bipolar disorders | 2.1 |
| 296.9 And all subcodes | Other and unspecified episodic mood disorder | 1.4 |
| 300.4 | Dysthymic disorder | 13.6 |
| 301.1 And all subcodes | Affective personality disorder | 0.2 |
| 309.0 | Adjustment disorder with depressed mood | 6.2 |
| 309.1 | Prolonged depressive reaction | 0.2 |
| 309.28 | Adjustment reaction with mixed anxiety and depressed mood | 15.7 |
| 311 And all subcodes | Depression, depressive disorder or state, NOS | 18.8 |
a
Subcodes are the codes that begin with the same digits, but have additional digits as well
b
Percent of all depression codes appearing in claims from individuals meeting the preferred case definition. Data are from a supplementary, detailed data set on a subset of the study population. The detailed data set included information on depression claims from industries with depression rates significantly above and below the population rate, and a random sample of claims from other industries. See “Methods” section. The distribution of diagnosis codes in all depression claims, including those from individuals with only one claim, was not materially different