Misdiagnosis: A Medical Negligence?
Diagnosis is an essential task performed by physicians. To treat a patient of an illness, the first step of treatment is his diagnosis.  
A diagnosis is the identification of a condition in the form of a disease or disorder. It is an examination conducted on the body of the patient to determine probable causes of his condition. 
Misdiagnosis is the primary reason for filing a medical negligence claim. The World Health Organization (WHO) recently prioritized patient safety areas and included diagnostic errors as a high-priority problem.
A misdiagnosis may relate to a wrong diagnosis, delayed diagnosis or failure of diagnosis. 
When a doctor's diagnosis leads to an error in treating the illness of the patient, which results in worsening the situation of the patient, shall amount to medical negligence. However, not all wrong/delayed diagnosis shall have a basis for a medical negligence claim.
A patient filing a case for medical negligence based on the misdiagnosis of the doctor has to establish the following:
  1. Doctor-patient relationship
  2. Failure of providing standard care in conducting a diagnosis on the patient. (Review to be based on expert opinion)
  3. Misdiagnosis causing an injury
  4. The patient must submit proof that the doctor did not correctly diagnose him and that a competent doctor a doctor of the similar speciality would have diagnosed correctly.
Generally, in case of a death, it is challenging to prove misdiagnosis in India since there is no proper mechanism to report it except under medical negligence. 
Also, to prove misdiagnosis, one would have to request for an autopsy, which is an expensive affair, and not everyone can afford it. Even if the family of the patient inclines towards requesting an autopsy, it is difficult for a layman who does not understand medical terms, to take a wise call. 
There are several reasons due to which misdiagnosis takes place. It is for the court to decide on the merits of each case individually whether it would be regarded as a defence available to the doctor, or would the doctor be held liable for medical negligence for misdiagnosis.
Different reasons/causes of misdiagnosis:
  1. The diagnosis was based on erroneous lab results conducted by a non-interested third party
  2. A piece of flawed equipment is used for conducting diagnosis
  3. A technician who wrongly administers the test 
  4. A secondary who misreads the scan
  5. Results of tests swapped between patients
  6. The limited-time associated with each patient 
For the above instances, if the concerned or diagnosing doctor is not liable, some other party will be liable. For example- the doctor is not responsible in case of 'results of tests being swapped' since it is the hospital staff who is involved in giving the doctors the test results.