Mr Gordon said Rotorua employers suspicious about a worker's sick leave normally set up counselling sessions to discuss possible issues. If there was no improvement, a warning could be issued.
Medical certificates identifying "the reasons for illness could enable enhanced support to be given from the employer" - however patient confidentiality must not be breached, Mr Gordon said.
New Zealand Medical Association chair Dr Mark Peterson supported a shift to a "workability note", where doctors detail which tasks an employee can perform.
This system already operated in the United Kingdom, and local doctors were increasingly taking up the practice, he said.
If someone employed as a checkout operator had an ankle operation, they "clearly can't work as a check-out operator because it involves standing all day".
"In that situation, the note would say 'This person's fit for work but only in a sedentary role'," Dr Peterson said.
A previous Treasury report estimated lost productivity due to ill health of workers cost between $1.44 billion and $1.76 billion each year.
Dr Peterson advised any employers who were suspicious about sick leave to speak to their employee. Doctors could be approached once patients gave their permission, he said. They only issued certificates when they had evidence someone was sick or injured, Dr Peterson said.
Despite this, employment lawyer Max Whitehead said some doctors issued certificates when they weren't needed.
"Rather than challenging a patient's honesty, doctors declare them as sick. This means the doctor gains financially and the powerless employer has to lose a day's work and pay a day's wages."
The Council of Trade Unions dismissed the claim.
Sick leave entitlements
Workers are entitled to five days' paid sick leave after six months under the Employment Relations Act
Following this, a worker is entitled to five days' sick leave for every 12 months
Sick leave can be taken if a worker is unwell or if someone who is dependent on them is sick (ie children or a spouse)
An employer can ask for proof of sickness or injury as soon as sick leave is taken
If a medical certificate is requested within the first three days of sick leave being taken, the employer must pay for the doctor's visit
The employer is forbidden to require the worker to visit a certain doctor
- Source: Ministry of Business, Innovation and Employment
