Integrative Diagnostic Model (IDM)

The integrative diagnostic model is a powerful, three-part methodology for diagnosis:

1. A voice-focused history;
2. Assessment of vocal capabilities and vocal limitations via elicitation;
3. Intense laryngeal examination.

Once these three parts of the evaluation are accomplished, the information gleaned from them must be integrated and correlated to arrive at a sound diagnosis.

Background of the Integrative Diagnostic Model

In an attempt to use only what is necessary and sufficient from the remarkable list of options available for evaluation, this model was developed and refined as an accurate and efficient process for diagnosing voice disorders. There are, of course, other models: a “traditional” one might include only a patient history and then proceed directly to examination of the larynx.

Comparison to the Traditional Model

The history, as told by the patient and family, is the “story line” of the problem. The examination is performed either with the time-honored laryngeal mirror or a fiberscope. In some circumstances, this traditional model is sufficient, such as when the disorder is obvious or acute. For chronic or elusive disorders, this traditional model often or even routinely does not provide enough information to make a complete diagnosis and to support patient understanding of their problem.

Comparison to the Technology-driven Model

The inadequacy of the traditional model has led some to dramatically expand the diagnostic process, and to divide an expanded list of diagnostic tasks among two or more clinicians. For example:

• Different clinicians (laryngologist, speech pathologist, neurologist, etc.) may each take a separate history, and then assess basic characteristics of the voice using auditory perception;
• They may then make acoustic, aerodynamic, electroglottographic, and even electromyographic machine measures of the acoustic, airflow, and neurophysiological output of the larynx;
• And finally examine the vocal folds using a state-of-the-art technique called laryngeal videostroboscopy.

This dramatic expansion of the diagnostic process could be dubbed the technology-driven or reductionistic model.

Problems with the Technology-driven Model

It can be argued that some items on the expanded list of diagnostic modalities are superfluous for diagnostic evaluation – and only encumber the process. Even when this technology-driven approach arrives at an accurate diagnosis, it may have done so with much more time and expense than necessary. Furthermore, unless machine measures are collected at the extremes of vocal capability and these various kinds of data are then skillfully integrated, the diagnosis may still be missed.

Simplicity is a virtue; hence, the formulation of the integrative diagnostic model. Based on extensive review of available diagnostic modalities and years of experience, some laryngologists may find it appropriate to “swim against the current” and resist, for purposes of diagnosis, methodologies that contribute little to the diagnostic process.

How the Integrative Diagnostic Model Works

1. In the first step, the patient’s history (story line of the problem) is mined for crucial, insight-giving information. It is not the quantity but the relevance of historical details that makes the difference. A focused, voice-relevant history attempts to go directly to necessary information and organize it in a coherent fashion. By the time the history has been completed, the physician should have generated a list of the two or three most likely diagnoses and be ready to move into the second step of the diagnostic process.
2. In the second step, the voice itself is assessed via a vocal capability battery. The idea here is to ask the voice to accomplish various tasks, each of which helps the physician assess one or another extreme of a particular vocal capability. We are interested, more than anything else, in the extremes of capability because that is where the “abnormal phenomenology” of each particular voice disorder is typically most clearly revealed. The vocal phenomenology that one hears during the vocal capability battery tends to support one or another of the preliminary diagnoses that came to mind during the history. At this point, the clinician is often already focusing in on the single most likely diagnosis, and rarely two or more remain in play.
3. In the third step, the larynx itself is subjected to intense visual imaging using the latest scopes available, and at times, topical anesthesia to permit a very close-up and precise view. Most often this includes videoendoscopic or videostroboscopic pictures of the larynx, subglottis, and trachea. Often, laryngeal examination is performed during the patient’s performance of the same extremes of vocal capability where abnormal vocal phenomenology was heard during vocal capability elicitation.
4. After the historical, vocal phenomenology, and laryngeal image information is collected from steps 1, 2, and 3, the physician must synthesize a diagnosis which fits the information gleaned from each part of the model. Infrequently, the physician will need to keep two potential diagnoses open, though one is usually favored over the other. In such a case, the patient is asked to see the speech pathologist who, through an extended interaction with the patient’s voice and vocal phenomenology, can add additional insight. Almost always, however, a firm diagnosis is reached at the conclusion of the initial consultation using the integrative diagnostic model, and its results are shared with the patient and family, along with the proposed treatment plan – whether medical treatment, behaviorial treatment (speech therapy), surgery, or multiple methods.

In an ideal world, key features of the IDM are

1. All three parts of the model preferably should be mastered by a single individual, rather than spreading it between two or three individuals who see the patient separately or “as a committee.”
2. Each step of the three-part model should be applied in a codified sequence within the same consultation to make the necessary integration and synthesis of the diagnosis as efficient as possible, within a single clinician visit.
3. The diagnostic model steadfastly keeps at bay other components beyond the crucial three, eliminating evaluations that might clutter the process of coming to an efficient and precise diagnosis by using only necessary and sufficient methods. Measurements or evaluations that do not fit the requirements of this diagnostic model continue to be seen as primarily for research purposes or for therapy monitoring or biofeedback, rather than as part of the diagnostic process itself.
4. The individual best able to master the diagnostic model due to innate capabilities and/or motivation in any particular site is the one who should take primary responsibility for diagnosis, whether that individual is a physician or speech pathologist. (In the latter case, there must of course be physician oversight, especially for medical and structural abnormalities.)