Before that happens, the patient is assessed by a prioritising clinician, who then makes a call on whether the patient gets a specialist assessment.
Of the 161,881 referrals that were assessed in this way, 87 per cent were accepted - with five per cent declined.
A further eight per cent were declined or held for other reasons, including insufficient information or so further investigation can be carried out.
The highest refusal rate was in the Bay of Plenty with 11.8 per cent of referrals declined because they were judged below the surgery threshold.
Surgery thresholds vary between DHBs, which take into account rankings on measures such as pain and mobility.
The Labour Party and surgeons have pointed to DHBs' lifting thresholds for access to elective surgery.
Bay of Plenty District Health Board chief operating officer Pete Chandler said the number of first specialist assessment (FSA) referrals being received had increased over the last four years.
"The number of FSAs received by our medical service has almost doubled," he said.
"Taking the monthly medical service figures for March as an example, in 2013 there were 916 referrals received. By March 2016 this figure had risen to 1682 a month. That represents an 84 per cent increase."
Mr Chandler said in terms of referrals accepted there had been a "huge increase" since 2016.
"Using an FSA acceptance rate of 84.5 per cent, that would represent 774 patients in March 2013 and 1421 in March 2016. That is an additional 647 patients a month receiving a FSA now compared to four years ago."
Though he said they were always trying to do more, these numbers represented a significant increase in access for the region's communities.
Mr Chandler said the high proportion of locum GPs in the Bay was known to increase referral rates to secondary care, many of which could have been managed within the community.
"We still have much work to do with GPs in providing good clinical support to aid their decision making about the appropriateness of referrals," he said.
Health Minister Dr Jonathan Coleman said the thresholds had always been adjusted from year to year, and were done so using tools to ensure fair and equitable access.
The newly released data shows the rate of referrals declined because they were judged below the surgery threshold varies between region.
In December last year, these rates were:
Northland - 0 per cent (84.7 per cent accepted)
Auckland - 5.5 per cent (84.6 per cent accepted)
Counties Manukau - 0.6 per cent (96.6 per cent accepted)
Waitemata - 7.3 per cent (85 per cent accepted)
Waikato - 2.6 per cent (84.3 per cent accepted)
Bay of Plenty - 11.8 per cent (84.5 per cent accepted)
Hawke's Bay - 3.2 per cent (82.5 per cent accepted)
Taranaki - 10.8 per cent (78.1 per cent accepted)
Hutt Valley - 10.7 per cent (76.3 per cent accepted)
Canterbury - 0 per cent (96 per cent accepted)
Southern - 9.9 per cent (87.4 per cent accepted)
The ministry has also released information by specialty type. Health Minister Dr Jonathan Coleman said the data release provided transparency.
"The data from national patient flow will help the sector better understand the outcomes of referrals to hospital specialists."
