To the Editor:
We thank Drs Callahan and Papani for their interest in our study. This commentary offers us the opportunity to reemphasize the significance of our review,1 in which we highlight the deficiency of universal, validated algorithms to identify pulmonary arterial hypertension (PAH) in administrative data and stress both the need for the development of those algorithms and for the modification of International Classification of Diseases (ICD) diagnosis codes to reflect our current PAH clinical classification system.
We agree unreservedly with the statement by Drs Callahan and Papani that “a larger issue may be that the ability to diagnose PAH accurately eludes many.” In fact, we draw attention to this point directly in our paper, noting “the complexity of the diagnosis of PAH even at a patient level” and citing prior work showing high rates of incorrect diagnoses, particularly when patients with PAH are managed outside of PAH referral centers.2 We also share Drs Callahan and Papani’s concern that many patients are being diagnosed with and treated for PAH without the necessary right heart catheterization, and that patients with non-group 1 pulmonary hypertension are being treated with pulmonary vasodilators outside of guideline recommendations, findings also seen in our group’s prior work.3 Clearly, research efforts are needed both to identify gaps in providers’ knowledge of PAH and to design interventions to address those gaps. While these research efforts warrant additional debate, they are beyond the scope of our study.
Despite the challenges of diagnosing PAH on a patient level, we maintain that improvements in both the PAH ICD diagnosis coding system and in the algorithms we utilize to capture PAH from that system are needed and will result in more precise discrimination of PAH from the other forms of pulmonary hypertension. Clinical coding in administrative data, despite its limitations, remains fundamental in performing epidemiologic studies, particularly for rare diseases such as PAH. Until we have better tools and analytics to leverage more complex and granular data, we must optimize ICD diagnosis codes to more accurately inform our understanding of PAH on a population level, an opinion shared by other leaders in the field of PAH.4, 5
We welcome ongoing discussions about how best to improve the diagnosis and management of this complex disease, and we look forward to additional research that will aid providers in the appropriate recognition, categorization, and treatment of pulmonary arterial hypertension.
Footnotes
FINANCIAL/NONFINANCIAL DISCLOSURES: See earlier cited article for author conflicts of interest.
References
- 1.Gillmeyer K.R., Lee M.M., Link A.P., Klings E.S., Rinne S.T., Wiener R.S. Accuracy of algorithms to identify pulmonary arterial hypertension in administrative data: a systematic review. Chest. 2019;155(4):680–688. doi: 10.1016/j.chest.2018.11.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Deano R.C., Glassner-Kolmin C., Rubenfire M. Referral of patients with pulmonary hypertension diagnoses to tertiary pulmonary hypertension centers: the multicenter RePHerral study. JAMA Intern Med. 2013;173(10):887–893. doi: 10.1001/jamainternmed.2013.319. [DOI] [PubMed] [Google Scholar]
- 3.Kim D., Lee K.M., Freiman M.R. Phosphodiesterase-5 inhibitor therapy for pulmonary hypertension in the United States: actual versus recommended use. Ann Am Thorac Soc. 2018;15(6):693–701. doi: 10.1513/AnnalsATS.201710-762OC. [DOI] [PubMed] [Google Scholar]
- 4.Link J., Glazer C., Torres F., Chin K. International Classification of Diseases coding changes lead to profound declines in reported idiopathic pulmonary arterial hypertension mortality and hospitalizations: implications for database studies. Chest. 2011;139(3):497–504. doi: 10.1378/chest.10-0837. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Fritz J.S., Smith K.A. The pulmonary hypertension consult: clinical and coding considerations. Chest. 2016;150(3):705–713. doi: 10.1016/j.chest.2016.05.010. [DOI] [PubMed] [Google Scholar]