Effect of change in coding rules on recording diabetes in hospital administrative datasets

Is the burden of diabetes in Australia underestimated? Comparison of diabetes ascertainment using linked administrative health data and an Australian diabetes registry

AIMS

To compare an algorithm for identifying individuals with diabetes using linked administrative health data with an Australian diabetes registry (National Diabetes Services Scheme, NDSS).

METHODS

This prospective cohort study linked baseline survey data for 266,414 individuals aged ≥ 45 years from the 45 and Up Study, Australia, to administrative health data sets. An algorithm for identifying individuals with diabetes was developed based on a combination of claims for dispensed insulin and glucose lowering medicines, diabetes-related hospital admissions, and diabetes-specific Medicare claims. Using the algorithm, participants were classified as 'certain', 'uncertain' or 'no' diabetes. The algorithm was compared to NDSS registrations as the reference standard.

RESULTS

Amongst the 45 and Up Study cohort, there were 53,669 individuals with certain diabetes identified by the algorithm, and 35,900 NDSS registrants. Compared with the NDSS, the sensitivity of the algorithm was 96.9% (95%CI 96.7-97.1) and specificity 91.8% (95%CI 91.7-91.9). Of the 53,699 individuals with diabetes identified by the algorithm, 34,864 were registered to the NDSS (PPV = 64.9%, 95%CI: 64.6-65.2).

CONCLUSIONS

This study demonstrates the value in using linked administrative data for diabetes monitoring and surveillance. National estimates using the NDSS alone may underestimate the diabetes burden by up to 35%.

Trends and Outcomes for Percutaneous Coronary Intervention and Coronary Artery Bypass Graft Surgery in New South Wales from 2008 to 2019

Risk profiles are changing for patients who undergo percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). In Australia, little is known of the nature of these changes in contemporary practice and of the impact on patient outcomes. We identified all CABG (n = 40,805) and PCI (n = 142,399) procedures in patients aged ≥18 years in New South Wales, Australia, during 2008 to 2019. Between 2008 and 2019, the age- and gender-standardized revascularization rate increased by 20% (from 267/100,000 to 320/100,000 population) for all revascularizations. The increase in revascularization was particularly driven by a 35% increase (from 194/100,000 to 261/100,000) in PCI, whereas the rate of CABG decreased by 20% (from 73/100,000 to 59/100,000). Mean age and the prevalence of co-morbidities (especially diabetes and atrial fibrillation) increased for patients with PCI in more recent years but remained consistently lower than for patients with CABG. CABGs performed in patients presenting with a non-ST-segment-elevation acute coronary syndrome halved from 34.3% to 18.7% during the study period, whereas PCIs in this group decreased from 36.5% to 29.6%. Risk-adjusted in-hospital mortality decreased by 7.5 deaths/1,000 procedures per month for CABG but remained unchanged for PCI. Risk-adjusted readmission rates were consistently higher for CABG than for PCI and did not change significantly over time. In conclusion, we observed a dramatic shift over time from CABG to PCI as the revascularization procedure of choice, with the patient base for PCI extending to older and sicker patients. There was a large decrease in mortality after CABG, whereas mortality after PCI remained unchanged.

Mortality is not increased with Diabetes in hospitalised very old adults: a multi-site review

Background

Few data exist regarding hospital outcomes in people with diabetes aged beyond 75 years. This study aimed to explore the association of diabetes with hospital outcome in the very old patient.

Methods

A retrospective review was conducted of all presentations of patients aged 65 years or more admitted to three Sydney teaching hospitals over 6 years (2012–2018), exploring primarily the outcomes of in-hospital mortality, and secondarily the outcomes of length of stay, the development of hospital-acquired adverse events and unplanned re-admission to hospital within 28 days of discharge. Demographic and outcome data, the presence of diabetes and comorbidities were determined from ICD10 coding within the hospital’s electronic medical record. Logistic and negative binomial regression models were used to assess the association of diabetes with outcome.

Results

A total of 139,130 separations (mean age 80 years, range 65 to 107 years; 51% female) were included, with 49% having documented comorbidities and 26.1% a diagnosis of diabetes.

When compared to people without diabetes, diabetes was not associated with increased odds of mortality (OR: 0.89 SE (0.02), p < 0.001). Further, because of a significant interaction with age, diabetes was associated with decreased odds of mortality beyond 80 years of age. While people with diabetes overall had longer lengths of stay (10.2 days SD (13.4) v 9.4 days SD (12.3), p < 0.001), increasing age was associated with shorter lengths of stay in people aged more than 90 years. Diabetes was associated with increased odds of hospital-acquired adverse events (OR: 1.09 SE (0.02), p < 0.001) and but not 28-day re-admission (OR: 0.88 SE (0.18), p = 0.523).

Conclusion

Diabetes has not been shown to have a negative impact on mortality or length of stay in hospitalised very old adults from data derived from hospital administrative records. This may allow a more measured application of diabetic guidelines in the very old hospitalised patient.

Accuracy of inter-hospital transfer information in Australian hospital administrative databases

Inter-hospital transfers improve care delivery for which sending and receiving hospitals both accountable for patient outcomes. We aim to measure accuracy in recorded patient transfer information (indication of transfer and hospital identifier) over 2 years across 121 acute hospitals in New South Wales, Australia. Accuracy rate for 127,406 transfer-out separations was 87 per cent, with a low variability across hospitals (10% differences); it was 65 per cent for 151,978 transfer-in admissions with a greater inter-hospital variation (36% differences). Accuracy rate varied by departure and arrival pathways; at receiving hospitals, it was lower for transfer-in admission via emergency department (incidence rate ratio = 0.52, 95% confidence interval: 0.51-0.53) versus direct admission. Transfer-out data were more accurate for transfers to smaller hospitals (incidence rate ratio = 1.06, 95% confidence interval: 1.03-1.08) or re-transfers (incidence rate ratio > 1.08). Incorporation of transfer data from sending and receiving hospitals at patient level in administrative datasets and standardisation of documentation across hospitals would enhance accuracy and support improved attribution of hospital performance measures.

Incidences and variations of hospital acquired venous thromboembolism in Australian hospitals: a population-based study

BACKGROUND

Data on hospital-acquired venous thromboembolism (HA-VTE) incidence, case fatality rate and variation amongst patient groups and health providers is lacking. We aim to explore HA-VTE incidences, associated mortality, trends and variations across all acute hospitals in New South Wales (NSW)-Australia.

METHODS

A population-based study using all admitted patients (aged 18-90 with a length of stay of at least two days and not transferred to another acute care facility) in 104 NSW acute public and private hospitals during 2002-2009. Poisson mixed models were used to derive adjusted rate ratios (IRR) in presence of patient and hospital characteristics.

RESULTS

Amongst, 3,331,677 patients, the incidence of HA-VTE was 11.45 per 1000 patients and one in ten who developed HA-VTE died in hospital. HA-VTE incidence, initially rose, but subsequently declined, whereas case fatality rate consistently declined by 22 % over the study period. Surgical patients were 128 % (IRR = 2.28, 95 % CI: 2.19-2.38) more likely to develop HA-VTE, but had similar case fatality rates compared to medical patients. Private hospitals, in comparison to public hospitals had a higher incidence of HA-VTE (IRR = 1.76; 95 % CI: 1.42-2.18) for medical patients. However, they had a similar incidence (IRR = 0.91; 95 % CI: 0.75-1.11), but a lower mortality (IRR = 0.59; 95 % CI: 0.47-0.75) amongst surgical patients. Smaller public hospitals had a lower HA-VTE incidence rate compared to larger hospitals (IRR < 0.68) but a higher case fatality rate (IRR > 1.71). Hospitals with a lower reported HA-VTE incidence tended to have a higher HA-VTE case fatality rate.

CONCLUSION

Despite the decline in HA-VTE incidence and case fatality, there were large variations in incidents between medical and surgical patients, public and private hospitals, and different hospital groups. The causes of such differences warrant further investigation and may provide potential for targeted interventions and quality improvement initiatives.