ICD-Confirmed Tardive Dyskinesia Diagnosis Seen in Only 5% of Suspected Cases

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“Tardive dyskinesia (TD) is a severe and persistent involuntary movement disorder associated with long-term antipsychotic treatment,” researchers wrote in BMC Psychiatry. “TD is likely underreported and misdiagnosed in routine practice, and there is a need to understand the proportion of patients who may experience TD but receive no formal diagnosis. This information could support the characterization of patient populations that may benefit from novel therapeutic interventions.”

Christoph U. Correll, MD, and colleagues sought to identify patients with diagnosed or undiagnosed TD and describe these patients’ characteristics. The researchers assessed demographic and clinical variables associated with an ICD-9/10 diagnosis of TD. Patients had schizophrenia-spectrum disorders, major depressive disorder with psychosis, or bipolar disorder with psychosis and were taking antipsychotics. The researchers reviewed mental state examinations to identify abnormal movements associated with TD and the presence of TD as documented in semi-structured EHR data.

The analysis included 32,558 adults, 1,301 (4.0%) of whom had either of the following within EHR data: the description of abnormal movements associated with TD (n=691) or documented TD (n=610). This group of 1,301 patients had a mean age of 46.8 and included more women (56.3%) than men.

Findings Based on ICD-TD Diagnosis

However, only 64 patients with documented abnormal movements—4.9%—had an ICD-confirmed TD diagnosis within EHR data.

When Dr. Correll and colleagues restricted the cohort to those with documented TD in EHR data, 56 (9.2%) had an ICD-TD diagnosis. Black race was associated with reduced odds of a documented ICD diagnosis compared with White race (odds ratio [OR]=0.46; 95% CI, 0.20–0.95; P=0.04). Receiving treatment at a community mental health center was associated with greater odds of an ICD diagnosis versus being treated at an academic medical center (adjusted OR=2.02; 95% CI, 1.09–3.74; P=0.03).

In a sensitivity analysis, the finding remained that an ICD-TD diagnosis was less common in patients of Black race (adjusted OR=0.45; 95% CI, 0.19–0.97; P=0.05) and more common in patients treated at a community mental healthcare center (adjusted OR=2.39; 95% CI, 1.24–4.61; P=0.01).

Primary Takeaways

According to Dr. Correll and colleagues, the primary finding from this study is that “less than 5% of patients with evidence of abnormal movements indicative of TD or specific mention of TD recorded during mental state examination also had an ICD-TD diagnosis.”

Further, even when the researchers limited the results to patients with a specific note about TD during a mental state examination, “evidence of underdiagnosis remained, in that ICD-TD diagnosis was recorded in less than 10% of patients,” they noted.

“Lack of a TD diagnosis in 95% of patients with evidence of abnormal movements associated with TD could represent a substantial missed opportunity for appropriate diagnosis and related evidence-based treatment,” Dr. Correll and colleagues emphasized.

Underscoring the Impact of Study Results

The findings have implications for both clinical research and the care of patients. Dr. Correll and colleagues noted that future research could employ EHR data to recognize patients with TD in lieu of a structured diagnostic code.

Further, the lack of a recorded ICD-TD diagnosis in 95% of patients who had likely evidence of TD may indicate “a substantial missed opportunity for treatment,” they wrote.

“This discordance is relevant in the context of billing procedures, which require an ICD diagnosis for reimbursement purposes and also evidence-based treatments in the U.S. healthcare system. Given that our total study period includes some calendar years before the approval of novel therapeutics for treatment of TD, lack of ICD recording may reflect lack of recognition or lack of perceived necessity to offer a diagnosis, which may be associated with increased stigma and lack of effective treatment options.”

Finally, the researchers noted that the lower likelihood of an ICD-TD diagnosis in Black patients compared with White patients may be due to several factors, including access to care, treatment quality, prescribing patterns regarding type and dosage of antipsychotic, as well as differences in drug metabolism.

“Regression analyses also identified community care setting as being associated with higher odds of documented ICD-TD diagnosis than academic settings,” Dr. Correll and colleagues wrote. “This finding may at first seem counterintuitive, as one would associate academic settings as those with higher quality of assessment and care than community care settings. While this might not be true when it comes to the assessment and diagnosis of TD, it is also possible that patients in community care settings are more likely severely and chronically mentally ill, or be treated with first-generation antipsychotics, putting them at higher risk for TD.”