Three doctors in southwestern China’s Guizhou province have been detained for the past seven months for allegedly misdiagnosing over 500 patients with black lung disease.

The three doctors from the black lung diagnosis unit at Guizhou Aerospace Hospital — the only hospital in the city of Zunyi that’s qualified to diagnose the disease — were arrested in November and have been detained ever since, according to a Tuesday article from a publication affiliated with the Chinese Medical Doctor Association.

A key piece of evidence for the doctors’ detention was an evaluation paper police presented to the hospital in October: It indicated that just 42 out of 547 patients diagnosed with black lung actually had the disease. The three doctors were detained for dereliction of duty as state employees. Police said the huge discrepancy should be ascribed to the doctors’ “severely irresponsible behavior,” which cost the local social insurance fund 30 million yuan ($4.6 million).

A district public prosecutor is reviewing the case to decide whether to press charges. Dereliction of duty as a state employee is a criminal offense in cases where irresponsible behavior or abuse of power causes significant financial damage to state-owned companies or other government interests. If the case is accepted and the doctors convicted, each faces a maximum of three years in prison.

There are currently an estimated 6 million black lung patients in China. The disease can result from inhaling mineral dust and lead to pulmonary fibrosis, or scarring of the lung tissue. Miners, foundry workers, and laborers in other heavy industries are especially vulnerable to the disease. Black lung is an occupational illness, meaning diagnosed patients can claim disability payments from the public social insurance fund, as well as the companies they work for.

After the doctors’ plight came to light, netizens began questioning whether misdiagnoses should be grounds for detention and criminal charges.

“Be careful, you can be put in jail for treating patients now!” quipped one user on social app WeChat. “If the supervising authorities see sentencing doctors as a solution to this incident — without carefully reviewing the case and our system more generally — then eventually there might not be any doctors who are willing to diagnose these occupational diseases.”

Mao Ling, a Shanghai-based pulmonologist specializing in black lung disease, told Sixth Tone that doctors make diagnoses from spots they observe on X-rays of patients’ lungs. She added, however, that there are many factors that can affect a doctor’s judgment, such as the quality of the X-ray — which largely depends on the medical technicians. Experience is also crucial, Mao added: If several doctors were to examine the same scan, their conclusions might be different.

Research shows that doctors with less than five years’ experience can only achieve around 44 percent accuracy when diagnosing black lung, while doctors with at least 15 years of experience are around 75 percent accurate.

According to the police evaluation, the three detained doctors made accurate diagnoses in just 8 percent of the 500-plus cases considered — despite each having worked in the medical profession for over 25 years, according to an appeal letter from the hospital included in the Tuesday article.

But the doctors’ lawyers are questioning the police evaluation. They argue that it is unfair for the authorities to consider just 547 black lung diagnoses from the total of 1,352 made at the hospital, saying they suspect the police were only interested in the questionable scans.

When local police began investigating the case in August 2016, they suspected the doctors of economic fraud: The provincial social insurance bureau had filed a complaint in which it accused Guizhou Aerospace Hospital doctors of colluding with workers to pocket funds intended for real black lung patients. But in late 2017, the official reason for the doctors’ detention was changed from economic fraud to dereliction of duty.

Feng Lihua, a lawyer at Zhongdun Law Firm in Beijing who specializes in medical cases, told Sixth Tone that it is rare to see doctors charged with dereliction of duty. “A crucial point of this case is whether the police evaluation is reliable and can be seen as solid evidence,” Feng said.

According to Mao, the Shanghai pulmonologist, doctors shouldn’t be the ones taking the blame for too many insurance payouts. “It’s not doctors creating the black lung patients who overburden the social insurance system,” she said. “Companies must meet national requirements for their work environments. For example, they should set up equipment that gets rid of dust and provide protective masks to their workers. The authorities, meanwhile, should impose stricter supervision.”

Sixth Tone’s phone calls to the Zunyi police went unanswered on Friday.

Editor: David Paulk.

(Header image: A doctor checks the X-ray of a patient with black lung disease at a hospital in Huaibei, Anhui province, Oct. 25, 2010. Wu He/VCG)