Cardiovascular risk prediction in type 2 diabetes before and after widespread screening: a derivation and validation study.

BACKGROUND: Until recently, most patients with diabetes worldwide have been diagnosed when symptomatic and have high cardiovascular risk, meaning most should be prescribed cardiovascular preventive medications. However, in New Zealand, a world-first national programme led to approximately 90% of eligible adults being screened for diabetes by 2016, up from 50% in 2012, identifying many asymptomatic patients with recent-onset diabetes. We hypothesised that cardiovascular risk prediction equations derived before widespread screening would now significantly overestimate risk in screen-detected patients. METHODS: New Zealanders aged 30-74 years with type 2 diabetes and without known cardiovascular disease, heart failure, or substantial renal impairment were identified from the 400 000-person PREDICT primary care cohort study between Oct 27, 2004, and Dec 30, 2016, covering the period before and after widespread screening. Sex-specific equations estimating 5-year risk of cardiovascular disease were developed using Cox regression models, with 18 prespecified predictors, including diabetes-related and renal function measures. Equation performance was compared with an equivalent equation derived in the New Zealand Diabetes Cohort Study (NZDCS), which recruited between 2000 and 2006, before widespread screening. FINDINGS: 46 652 participants were included in the PREDICT-1° Diabetes subcohort, of whom 4114 experienced first cardiovascular events during follow-up (median 5·2 years, IQR 3·3-7·4). 14 829 (31·8%) were not taking oral hypoglycaemic medications or insulin at baseline. Median 5-year cardiovascular risk estimated by the new equations was 4·0% (IQR 2·3-6·8) in women and 7·1% (4·5-11·2) in men. The older NZDCS equation overestimated median cardiovascular risk by three times in women (median 14·2% [9·7-20·0]) and two times in men (17·1% [4·5-20·0]). Model and discrimination performance measures for PREDICT-1° Diabetse equations were also significantly better than for the NZDCS equation (eg, for women: R2=32% [95% CI 29-34], Harrell's C=0·73 [0·72-0·74], Royston's D=1·410 [1·330-1·490] vs R2=24% [21-26], C=0·69 [0·67-0·70], and D=1·147 [1·107-1·187]). INTERPRETATION: International treatment guidelines still consider most people with diabetes to be at high cardiovascular risk; however, we show that recent widespread diabetes screening has radically changed the cardiovascular risk profile of people with diabetes in New Zealand. Many of these patients have normal renal function, are not dispensed glucose-lowering medications, and have low cardiovascular risk. These findings have clear international implications as increased diabetes screening is inevitable due to increasing obesity, simpler screening tests, and the introduction of new-generation glucose-lowering medications that prevent cardiovascular events. Cardiovascular risk prediction equations derived from contemporary diabetes populations, with multiple diabetes-related and renal function predictors, will be required to better differentiate between low-risk and high-risk patients in this increasingly heterogeneous population and to inform appropriate non-pharmacological management and cost-effective targeting of expensive new medications. FUNDING: Health Research Council of New Zealand, Heart Foundation of New Zealand, and Healthier Lives National Science Challenge.

Cardiovascular disease risk prediction equations in 400 000 primary care patients in New Zealand: a derivation and validation study.

BACKGROUND: Most cardiovascular disease risk prediction equations in use today were derived from cohorts established last century and with participants at higher risk but less socioeconomically and ethnically diverse than patients they are now applied to. We recruited a nationally representative cohort in New Zealand to develop equations relevant to patients in contemporary primary care and compared the performance of these new equations to equations that are recommended in the USA. METHODS: The PREDICT study automatically recruits participants in routine primary care when general practitioners in New Zealand use PREDICT software to assess their patients' risk profiles for cardiovascular disease, which are prospectively linked to national ICD-coded hospitalisation and mortality databases. The study population included male and female patients in primary care who had no prior cardiovascular disease, renal disease, or congestive heart failure. New equations predicting total cardiovascular disease risk were developed using Cox regression models, which included clinical predictors plus an area-based deprivation index and self-identified ethnicity. Calibration and discrimination performance of the equations were assessed and compared with 2013 American College of Cardiology/American Heart Association Pooled Cohort Equations (PCEs). The additional predictors included in new PREDICT equations were also appended to the PCEs to determine whether they were independent predictors in the equations from the USA. FINDINGS: Outcome events were derived for 401 752 people aged 30-74 years at the time of their first PREDICT risk assessment between Aug 27, 2002, and Oct 12, 2015, representing about 90% of the eligible population. The mean follow-up was 4·2 years, and a third of participants were followed for 5 years or more. 15 386 (4%) people had cardiovascular disease events (1507 [10%] were fatal, and 8549 [56%] met the PCEs definition of hard atherosclerotic cardiovascular disease) during 1 685 521 person-years follow-up. The median 5-year risk of total cardiovascular disease events predicted by the new equations was 2·3% in women and 3·2% in men. Multivariable adjusted risk increased by about 10% per quintile of socioeconomic deprivation. Maori, Pacific, and Indian patients were at 13-48% higher risk of cardiovascular disease than Europeans, and Chinese or other Asians were at 25-33% lower risk of cardiovascular disease than Europeans. The PCEs overestimated of hard atherosclerotic cardiovascular disease by about 40% in men and by 60% in women, and the additional predictors in the new equations were also independent predictors in the PCEs. The new equations were significantly better than PCEs on all performance metrics. INTERPRETATION: We constructed a large prospective cohort study representing typical patients in primary care in New Zealand who were recommended for cardiovascular disease risk assessment. Most patients are now at low risk of cardiovascular disease, which explains why the PCEs based mainly on old cohorts substantially overestimate risk. Although the PCEs and many other equations will need to be recalibrated to mitigate overtreatment of the healthy majority, they also need new predictors that include measures of socioeconomic deprivation and multiple ethnicities to identify vulnerable high-risk subpopulations that might otherwise be undertreated. FUNDING: Health Research Council of New Zealand, Heart Foundation of New Zealand, and Healthier Lives National Science Challenge.

Acute coronary syndrome registry enrolment status: differences in patient characteristics and outcomes and implications for registry data use (ANZACS-QI 36).

AIMS: Clinical registry-derived data are widely used to represent patient populations. In New Zealand (NZ), a national registry-the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry-aims to include all patients undergoing coronary angiography; other acute coronary syndrome (ACS) patients are also registered but without complete capture. This study compares national hospitalization data of all first-time ACS admissions in NZ with patients in the ANZACS-QI registry, to investigate the use of clinical registry-derived data in research and in assessing clinical care. METHODS AND RESULTS: Patients admitted with first-time ACS in the NZ National Hospitalisation Dataset between 1 January 2015 and 31 December 2016 were included. Clinical characteristics and time to 12-month clinical outcomes were compared between patients captured and not-captured in the registry. A total of 16 569 patients were admitted with first-time ACS, median age 69 years, 61% male; 60% (n = 9918) were enrolled in ANZACS-QI. Registry-captured patients were younger, more often male, and with a lower comorbidity burden than non-captured patients. Overall, 16% patients died within 12 months, 15% experienced a non-fatal cardiovascular (CV) readmission, and 28% either died or were readmitted. Patients not captured in the registry were more than twice as likely to have experienced death or a non-fatal CV readmission within 12 months as captured patients. CONCLUSIONS: First-time ACS patients captured in the ANZACS-QI registry had very different clinical characteristics and outcomes than those not captured. Cardiovascular registry-derived data are dependent on registry design and may not be representative of the wider patient population; this must be considered when using registry-derived data.

Tinnitus prevalence in New Zealand.

AIM: There is a lack of consensus in the international literature pertaining to the prevalence of tinnitus for the overall population, as well as sex and age sub-groups, suggesting the need for country-specific prevalence estimates. We aim to find prevalence estimates of tinnitus that are representative of the New Zealand population. METHOD: We obtained data from random-digit dialled telephone surveys of households, conducted by Roy Morgan Research Limited between August, 2007, and July, 2013, for people aged ≥ 14 years in New Zealand (n=69,976). As part of the survey, participants were asked whether they have had tinnitus in the last 12 months. The response options were "yes" or "no". Estimates were standardised to the New Zealand population structure based on the 2013 national census. Sex, age and ethnic differences were explored. RESULTS: The overall weighted prevalence for any tinnitus was 6.0% in the total New Zealand population age ≥ 14 years. Tinnitus was higher among males (6.5%) compared to females (5.5%). Males were 55% more likely to report tinnitus compared to females among young adults aged 14 to 24 years, while males were 32% more likely to report tinnitus compared to females among adults aged 50 to 64 years. Tinnitus prevalence increased with age, peaking at 13.5% for older adults aged ≥ 65 years. Adults aged ≥ 65 years are three times more likely to report tinnitus than people aged below 65 years. Tinnitus prevalence was highest among people identifying as European (7.05%) and lowest among people identifying as Asian (1.00%). CONCLUSION: This is the first nationally representative study of tinnitus prevalence in New Zealand and largest study sample internationally for tinnitus prevalence to date. Tinnitus is a public health problem affecting approximately 207,000 people in the New Zealand population aged ≥ 14 years. This study has highlighted the importance of sex and age in defining a high-risk tinnitus population, but our knowledge falls short of profiling their ethnic and social-economic characteristics.