Therapy for alpha1-antitrypsin deficiency: pharmacology and clinical recommendations

Impact of a clinical decision support system in an electronic health record to enhance detection of α₁-antitrypsin deficiency

BACKGROUND

Because α(1)-antitrypsin deficiency (AATD) is underrecognized, strategies to enhance guideline-based diagnostic testing are warranted.

METHODS

We studied the impact of issuing a guideline-based alert within an electronic health record (EHR) to test for AATD on the rate of testing for and detection of AATD. For patients at the Cleveland Clinic whose physician-ordered pulmonary function test results showed airflow obstruction, the rates of testing for and detection of AATD were determined during a baseline (prealert) period and again after implementing the alert.

RESULTS

During the baseline period, among 979 eligible subjects, 4.7% were tested; 8.9% of those who had phenotype testing performed were found to have AATD (serum levels < 100 mg/dL), of whom 3.2% had the PI*ZZ genotype. After the alert, among the 624 eligible subjects, the rate of testing increased severalfold (15.1%, P < .001), though neither the rate of detecting AATD (5.3%) nor PI*ZZ (2.6%) differed from the rates during the baseline period. Having an alternate diagnosis (other than asthma) that could explain airflow obstruction (eg, congestive heart failure, sarcoidosis, Langerhans cell histiocytosis) was associated with a lower rate of testing (P = .041), while carrying a diagnosis of asthma tended to increase the testing frequency (P = .15). Multivariate analysis showed that younger age and a smoking history were associated with being tested.

CONCLUSIONS

Issuing an alert within an EHR was associated with a severalfold increase in the frequency of testing for α(1)-antitrypsin without a higher rate of diagnosing severe AATD. While the lack of more frequent diagnosis of AATD may reflect a high rate of baseline detection, these results prompt consideration of additional strategies to enhance detection of AATD.

Detection of alpha-1 antitrypsin deficiency: a review

Screening studies reveal a much larger number of individuals expected to have alpha-1 antitrypsin deficiency than is clinically recognized, with estimates that only about 2-10% of such individuals have been diagnosed. In the context that recognition of alpha-1 antitrypsin may prompt specific interventions (e.g., smoking avoidance, testing of family members, genetic counseling, and consideration of augmentation therapy), diagnosis is important, inviting much attention for efforts to identify affected individuals. Strategies to identify affected individuals include both population-based screening and targeted detection, and available studies have employed both approaches, though large-scale population-based screening is challenging. As reviewed in this paper, targeted-detection studies have generally produced a higher rate of detecting disease, and tend to be more successful with easier sampling techniques. Strategies to enhance detection in targeted studies have included awareness campaigns, easy testing techniques (such as evaluation of dried blood spots and home, confidential testing), and inclusive criteria for testing which span the full spectrum of clinical manifestations of alpha-1 antitrypsin deficiency.