The Sydney anaesthesiologist went to work thinking he would come home to see his beautiful wife, fellow doctor Vanessa Pattullo.

"I did come home to find my beautiful wife, but she was no longer alive," Dr Pattullo said on Wednesday.

Vanessa, 42, had recurrent, aggressive leukaemia and faced a death by asphyxiation.

Rather than suffer that fate, she chose to take her own life.

Dr Pattullo described himself as Vanessa's voice before a NSW upper house inquiry considering draft voluntary assisted dying laws.

He said it was "very clear" she would have chosen voluntary assisted dying if it had been legal.

"Vanessa (was) forced to take her own life alone and without saying goodbye to her loved ones because the laws of this state," he said.

"I always knew my wife was going to die before me.

"But I wanted that day to be with me holding her hand and her holding my hand, so we both knew everything would be OK."

The committee was urged by advocates, doctors and nurses, lawyers and researchers to pass the bill, which the upper house is considering after the Legislative Assembly passed it following four days of debate last month.

Dr Pettullo said he was lucky to have a strong support network but others would carry the devastation of a terminally ill relative's suicide in isolation.

Making voluntary assisted dying legal would "bring it into the open" and ensure relatives could access proper counselling, he said.

Dying With Dignity advocate Shayne Higson told the committee that voluntary assisted dying could prolong some people's lives.

She gave an example of a multiple sclerosis sufferer who killed himself earlier than he otherwise would have because he may have lost the ability to do so if his condition had progressed further.

"If we had had voluntary assisted dying then he would have had more time to spend with his wife and his two young children," Ms Higson said.

Amid opponents' arguments that the bill would allow elder abuse, the committee heard the bill already struck the right balance and did not require protections.

"There is nothing uniquely special or vulnerable about dying people in NSW to warrant adding additional requirements and safeguards above and beyond those (in other states)," Dying With Dignity NSW president Penny Hackett said.

Adding more onerous criteria or processes, such as at the medical assessment stage, would "significantly reduce the ability of dying people to access the regime".

"It would simply increase the suffering of people who are already struggling with a significant burden of illness without adding any meaningful protections against abuse," she said.

The draft law requires two doctors to sign off on a patient's request to access voluntary assisted dying.

The patient must be terminally ill and likely to die within six months or a year if they have a neurodegenerative condition.

The sickness must be causing them intolerable suffering.

The bill forbids doctors from initiating conversations about voluntary assisted dying unless they also suggest treatment options and palliative care.

Doctors who conscientiously object won't be forced to take part.

The option will only be available to adults who live in NSW and they must have capacity to make the decision.

The upper house inquiry will sit throughout December and will report back before the first sitting day of 2022.

If the historic reform secures majority support in the upper house next year, it will make NSW the last state in Australia to embrace voluntary assisted dying.

Australian Associated Press