Use of a Handheld Ultrasonographic Device to Identify Heart Failure and Pulmonary Disease in Rural Africa

Abstract

Importance: Agreement in lung ultrasonography findings between clinicians using a handheld ultrasonographic device and expert sonographers using a high-end ultrasonographic machine has not been studied in sub-Saharan Africa.

Objective: To determine the agreement in ultrasonographic findings and diagnoses between primary care clinicians trained in lung ultrasonography, board-certified expert sonographers, and senior physicians.

Design, setting, and participants: This cross-sectional single-center study was conducted from February 1, 2022, to April 30, 2023 at a referral center in rural Tanzania. Individuals 5 years or older with respiratory symptoms and at least 2 distinct respiratory signs or symptoms were eligible. A total of 459 individuals were screened.

Exposures: Participants provided their medical history and underwent a clinical examination and lung ultrasonography performed by a clinician, followed by a lung ultrasonography performed by an expert sonographer, and finally chest radiography and a final evaluation performed by a senior physician. Other tests, such as echocardiography and Mycobacterium tuberculosis testing, were conducted on the decision of the physician. Clinicians received 2 hours of instruction and three 2-hour sessions of clinical training in the use of a handheld lung ultrasonographic device; expert sonographers were board-certified.

Main outcomes and measures: Percentage agreement and Cohen κ coefficient for sonographic findings and diagnoses compared between clinicians and expert sonographers, and between clinicians and senior physicians.

Results: The median (IQR) age of 438 included participants was 54 (38-66) years, and 225 (51%) were male. The median (range) percentage agreement of ultrasonographic findings between clinicians and expert sonographers was 93% (71%-99%), with κ ranging from -0.003 to 0.83. Median (range) agreement of diagnoses between clinicians and expert sonographers was 90% (50%-99%), with κ ranging from -0.002 to 0.76. Between clinicians and senior physicians, median (range) agreement of diagnoses was 89% (55%-90%), with κ ranging from -0.008 to 0.76. Between clinicians and senior physicians, diagnosis agreements were 85% (κ, 0.69) for heart failure, 78% (κ, 0.57) for definite or probable tuberculosis, 50% (κ, 0.002) for viral pneumonia, and 56% (κ, 0.06) for bacterial pneumonia.

Conclusions and relevance: In this cross-sectional study, the agreement of ultrasonographic findings between clinicians and sonographers was mostly substantial. Between clinicians and senior physicians, agreement was substantial in the diagnosis of heart failure, moderate in the diagnosis of tuberculosis, but slight in the diagnosis of pneumonia. These findings suggest that handheld ultrasonographic devices used in addition to clinical examination may support clinicians in diagnosing cardiac and pulmonary diseases in rural sub-Saharan Africa.