The 13 incidents were related to four categories of care - patient falls, medication, healthcare associated infection and clinical process (assessment, diagnosis, treatment and general care).
There were four falls, one resulting in the death of a patient, one hospital-acquired infection, one medication-related event resulting in the death of a patient, two events resulting in harm from misdiagnosis and five errors in maternity services clinical processes, resulting in the deaths of three unborn babies and harm to two patients.
All errors happened at Rotorua Hospital. There were no reported events at Taupo Hospital.
Lakes District Health Board spokeswoman Sue Wilkie said the deaths of the intrauterine babies were "multifactorial but a component of each related to antenatal referral and follow-up processes".
She said the medication-related event which resulted in the death of a patient involved the prescription of anticoagulant medicines.
In a written statement Lakes DHB said while it endeavoured to provide high quality services to its community, it acknowledged and "sincerely regrets that at times harm occurs".
The errors have prompted several changes, including a new falls assessment and care plan document, a plan to improve staff awareness of processes in place, particularly those relating to patients with limited English, and early recognition of diagnostic complexity to include low thresholds for early referral to tertiary specialty services.
Other improvements included a maternity antenatal clinic quality improvement project, the establishment of a network of falls link nurses in wards and national communication regarding interpretation of clinical guidelines.
Lakes DHB quality, risk and clinical governance director Dr Sharon Kletchko said the board had approved a programme for "speaking up for safety and professional accountability, which is an evidence-based framework that builds a high-performance culture of safety and reliability and addresses individual behaviours that may undermine it".
"This programme is part of Lakes District Health Board's response to serious adverse events and our quest for zero preventable harm to our patients.
"Our District Health Board is taking positive steps with this programme to support our clinicians to do the right thing and to learn from these serious adverse events."
Nationally, 542 adverse events were reported by district health boards between 2016 and this year, an increase on the 520 events reported the year before.
Commission chairman Professor Alan Merry said the impact on the people involved in these incidents - and their families - was huge.
He acknowledged that more could be done to improve safety in hospitals and health providers by looking at the learning process - and working with people who have been affected by an adverse event in the past.
"Partnering with consumers and whanau in the review and learning process is pivotal to improving quality and safety,'' he said.
"Consumers may be able to perceive care transition and process issues including service quality that occur before, during and after adverse events that are less likely to be identified as providers."
Lakes DHB serious adverse events 2016/17:
- Four falls resulting in one death and three harms
- One hospital-acquired infection
- One patient medication-related event resulting in death
- Seven patient clinical process related events. Of those, two events resulted in harm from misdiagnosis. Five events were related to maternity services clinical processes, resulting in three deaths and two harms.
