Computer-Assisted Diagnostic Interview (CADI) uses the computer to assist, enhance and improve TDI. CADI was first presented at the APA's annual meeting in 1996. CADI modifies both data collection and data processing.
Data collection is done with a protocol. The use of protocols during TDI is nearly universal. After examining dozens of protocols from many facilities, conferring with colleagues and consulting textbooks, I developed a three-page protocol that uses 250 data items (most protocols use 50 to 150 items). CADI protocol comes in two forms, printed and computerized. The clinician fills in the printed form either during or at the end of a TDI. All protocol items are number-coded so that the clinician or an assistant can enter the data into the computer.
Each page of the protocol is displayed on the computer screen, one item at a time. Sample questions are provided alongside each item to help beginning clinicians avoid leading or close-ended questions. Numeric answers are entered by choosing an integer from multiple choices. Narrative answers are typed and stored as text. The user can jump to other screens and change an answer by overwriting.
If the user is only interested in diagnosis, areas such as family and personal history can be ignored and only the Mental Status and DSM diagnostic criteria would need to be entered. The CADI computer program processes data by comparing all items in the data base with all DSM algorithms for adult disorders and finding all diagnoses. CADI then provides the following output: a) Match: the data base matches with enough DSM criteria to make the diagnoses.
b) Partial match: the incomplete data base matches some DSM criteria, but not enough to rule the diagnosis either in or out. CADI specifies which unevaluated criteria are needed to complete the evaluation.
c) No match: the data base has enough negative matches with DSM criteria to rule out these diagnoses.CADI's Place in Psychiatric Practice
CADI occupies a place between the less-than-reliable TDI and the reliable but time-consuming structured interview like the Structured Clinical Interview for DSM (SCID).
My UCLA inpatient service is staffed by four residents, three medical students and me. We use CADI to collect, process and analyze our data bases.
My experience is that CADI takes about the same amount of time as the TDI. Collecting a larger data base takes more time, but data can be entered faster by checking off items rather than writing answers; the program makes the diagnosis and prints the write-up, saving time with those tasks.
CADI can have a salutary influence on our cognitive attitudes: it leads us to 1) collect a complete data base instead of stopping when we believe that we have minimally enough information; 2) strive for accuracy in obtaining data during the interview; 3) consider a broad differential diagnosis rather than a narrow single diagnosis.
In addition to clinical and research uses, CADI is also useful for evaluating quality/utilization management. With its parameters for measuring change (current scales built into CADI include the Positive and Negative Syndrome Scale for Schizophrenia, Beck and Hamilton Depression Scales, Childhood Autism Rating Scale and the Abnormal Involuntary Movements Scale), we can assess change over time. For managed care, this means that we can justify admissions and uphold requests for extensions of stay through measurements showing that the patient has not yet improved enough for discharge.