Uncovering long-term illness in the community

Hospital records fail to capture more than half of New Zealanders living with multiple long-term health conditions, a new study has found. Researchers say this means the extent of complex health needs in communities is being underestimated.

After linking general practitioner (GP) and hospital records, University of Auckland researchers found that nearly one in three adults had two or more long-term health conditions. But less than half of those cases would have been detected using hospital data alone, with many conditions recorded only in GP data.

Researchers analysed linked GP and hospital records from more than 374,000 adults to better understand multimorbidity, the presence of two or more long-term conditions.

The study found that 30.8 percent of adults had multimorbidity, with the figure rising to more than 60 percent among those aged 65 to 74.

Of the 115,320 people found to have multiple conditions, 52,867 were captured in hospital records while 62,453 were recorded only in GP data.

The research was led by Honorary Professor Susan Wells and conducted by researchers from Waipapa Taumata Rau, University of Auckland, in collaboration with ProCare Primary Health Organisation (PHO).

Associate Professor Katrina Poppe, the paper's corresponding author from the University's Department of Medicine, says the study highlights gaps in the data used to guide health service planning.

Many conditions contributing to multimorbidity, such as hypertension, joint or spinal disorders, chronic lung disease, diabetes and metabolic disorders, are largely managed in primary care and may never result in hospital admission, meaning they appear only in general practice records.

The team analysed linked records from adults enrolled with ProCare, the country's largest PHO, and compared cases found through hospital records alone, GP records alone and a combination of both.

Hospital records underestimated multimorbidity more often for women and older adults, the study found.

Poppe says hospital records provide only part of the picture of population health needs.

"If the data used to plan and resource healthcare doesn't include what's happening in primary care, it's not going to reflect the true level of need."

She says the consequences extend beyond measurement.

"Without the combination of primary care and hospital data, we will continue to underrate the complexity of care and health system resources required to support the needs of this important and growing group of patients."

• The study