Prevalence and Incidence of Statin Use and 3-Year Adherence and Discontinuation Rates Among Older Adults With Dementia

Cholesterol Lowering in Older Adults: Should We Wait for Further Evidence?

PURPOSE OF REVIEW

Current guidelines for primary and secondary prevention of cardiovascular events in adults up to age 75 years are well-established. However, recommendations for lipid-lowering therapies (LLT), particularly for primary prevention, are inconclusive after age 75. In this review, we focus on adults ≥ 75 years to assess low-density lipoprotein-cholesterol (LDL-C) as a marker for predicting atherosclerotic cardiovascular disease (ASCVD) risk, review risk assessment tools, highlight guidelines for LLT, and discuss benefits, risks, and deprescribing strategies.

RECENT FINDINGS

The relationship between LDL-C and all-cause mortality and cardiovascular outcomes in older adults is complex and confounded. Current ASCVD risk estimators heavily depend on age and lack geriatric-specific variables. Emerging tools may reclassify individuals based on biologic rather than chronologic age, with coronary artery calcium scores gaining popularity. After initiating LLT for primary or secondary prevention, target LDL-C levels for older adults are lacking, and non-statin therapy thresholds remain unknown, relying on evidence from younger populations. Shared decision-making is crucial, considering therapy's time to benefit, life expectancy, adverse events, and geriatric syndromes. Deprescribing is recommended in end-of-life care but remains unclear in fit or frail older adults. After an ASCVD event, LLT is appropriate for most older adults, and deprescribing can be considered for those approaching the last months of life. Ongoing trials will guide statin prescription and deprescribing among older adults free of ASCVD. In the interim, for adults ≥ 75 years without a limited life expectancy who are free of ASCVD, an LLT approach that includes both lifestyle and medications, specifically statins, may be considered after shared decision-making.

Did Australia's COVID-19 Restrictions Impact Statin Incidence, Prevalence or Adherence?

COVID-19 restrictions may have an unintended consequence of limiting access to cardiovascular care. Australia implemented adaptive interventions (eg, telehealth consultations, digital image prescriptions, continued dispensing, medication delivery) to maintain medication access. This study investigated whether COVID-19 restrictions in different jurisdictions coincided with changes in statin incidence, prevalence and adherence. Analysis of a 10% random sample of national medication claims data from January 2018 to December 2020 was conducted across 3 Australian jurisdictions. Weekly incidence and prevalence were estimated by dividing the number statin initiations and any statin dispensing by the Australian population aged 18-99 years. Statin adherence was analyzed across the jurisdictions and years, with adherence categorized as <40%, 40%-79% and ≥80% based on dispensing per calendar year. Overall, 309,123, 315,703 and 324,906 people were dispensed and 39,029, 39,816, and 44,979 initiated statins in 2018, 2019, and 2020 respectively. Two waves of COVID-19 restrictions in 2020 coincided with no meaningful change in statin incidence or prevalence per week when compared to 2018 and 2019. Incidence increased 0.3% from 23.7 to 26.2 per 1000 people across jurisdictions in 2020 compared to 2019. Prevalence increased 0.14% from 158.5 to 159.9 per 1000 people across jurisdictions in 2020 compared to 2019. The proportion of adults with ≥80% adherence increased by 3.3% in Victoria, 1.4% in NSW and 1.8% in other states and territories between 2019 and 2020. COVID-19 restrictions did not coincide with meaningful changes in the incidence, prevalence or adherence to statins suggesting adaptive interventions succeeded in maintaining access to cardiovascular medications.

Validity of three risk prediction models for dementia or cognitive impairment in Australia

BACKGROUND

no studies have compared the predictive validity of different dementia risk prediction models in Australia.

OBJECTIVES

(i) to investigate the predictive validity of the Australian National University-Alzheimer's Disease Risk Index (ANU-ADRI), LIfestyle for BRAin Health (LIBRA) Index and cardiovascular risk factors, ageing and dementia study (CAIDE) models for predicting probable dementia/cognitive impairment in an Australian cohort. (ii) To develop and assess the predictive validity of a new hybrid model combining variables from the three models.

METHODS

the Hunter Community Study (HCS) included 3,306 adults aged 55-85 years with a median follow-up of 7.1 years. Probable dementia/cognitive impairment was defined using Admitted Patient Data Collection, dispensing of cholinesterase inhibitors or memantine, or a cognitive test. Model validity was assessed by calibration and discrimination. A hybrid model was developed using deep neural network analysis, a machine learning method.

RESULTS

120 (3.6%) participants developed probable dementia/cognitive impairment. Mean calibration by ANU-ADRI, LIBRA, CAIDE and the hybrid model was 19, 0.5, 4.7 and 3.4%, respectively. The discrimination of the models was 0.65 (95% CI 0.60-0.70), 0.65 (95% CI 0.60-0.71), 0.54 (95% CI 0.49-0.58) and 0.80 (95% CI 0.78-0.83), respectively.

CONCLUSION

ANU-ADRI and LIBRA were better dementia prediction tools than CAIDE for identification of high-risk individuals in this cohort. ANU-ADRI overestimated and LIBRA underestimated the risk. The new hybrid model had a higher predictive performance than the other models but it needs to be validated independently in longitudinal studies.

Cost-Effectiveness, Burden of Disease and Budget Impact of Inclisiran: Dynamic Cohort Modelling of a Real-World Population with Cardiovascular Disease

OBJECTIVE

We aimed to estimate the cost-effectiveness, burden of disease and budget impact of inclisiran added to standard-of-care lipid-lowering therapy in the real-world secondary cardiovascular prevention population in Switzerland.

METHODS

An open-cohort Markov model captured event risks by sex, age and low-density lipoprotein cholesterol based on epidemiological and real-world data. Low-density lipoprotein cholesterol reduction with add-on inclisiran was based on trial results and translated to meta-analysis-based relative risks of cardiovascular events. Unit costs for 2018 were based on publicly available sources, adopting a Swiss healthcare system perspective. Price assumptions of Swiss francs (CHF) 500 and CHF 3,000 per dose of inclisiran were evaluated, combined with uptake assumptions for burden of disease and budget impact. The assessment of cost-effectiveness used a discount rate of 3% per year. We performed deterministic and probabilistic sensitivity analyses, and extensive scenario analyses.

RESULTS

Patients treated with inclisiran gained a 0.291 qualityadjusted life-year at an incremental cost per QALY gained of CHF 21,107/228,040 (life-long time horizon, discount rate 3%) under the lower/higher price. Inclisiran prevented 1025 cardiovascular deaths, 3425 acute coronary syndrome episodes, and 1961 strokes in 48,823 patients ever treated during 10 years; the 5-year budget impact was CHF 49.3/573.4 million under the lower/higher price. Estimates were sensitive to calibration targets and treatment eligibility; burden of disease/budget impact results also to uptake. Limitations included uncertainties about model assumptions and the size and characteristics of the population modelled.

CONCLUSIONS

Inclisiran may be cost-effective at a willingness to pay of CHF 30,000 if priced at CHF 500; a threshold upwards of CHF 250,000 will be required if priced at CHF 3000. Inclisiran could enable important reductions in cardiovascular burden particularly under broader eligibility with a budget impact range from moderate to high depending on price.

Statin discontinuation in persons with and without Alzheimer's disease

Background

Although statin use is reported to decrease after dementia diagnosis, time to statin discontinuation and factors associated with discontinuation have not been studied in persons with Alzheimer’s disease (AD). We compared the risk of discontinuation and factors associated with discontinuation, including secondary and primary prevention indication, in statin users with and without AD.

Methods

The register-based Medication Use and Alzheimer’s Disease (MEDALZ) cohort includes community dwellers with a clinically verified AD diagnosed during 2005–2011 in Finland. On the AD diagnosis date (index date), each person with AD was matched with a comparison person without AD. We included 25,137 people with AD and 22,692 without AD who used statin on the index date or initiated within 90 days after. Cox regression models restricted to 4-year follow-up were conducted.

Result

The median time to statin discontinuation was 1.46 years in people with AD and 1.36 years in people without AD. People with AD were more likely to discontinue than people without AD (adjusted HR (aHR) 1.20 (95% CI 1.18–1.24)). This was observed for both primary (aHR 1.11 (1.06–1.16)) and secondary prevention (aHR 1.30 (1.25–1.35)) purpose. Factors associated with discontinuation included higher age and female gender, whereas concomitant cardiovascular drug use and previous statin use were associated with decreased risk.

Conclusion

The absolute difference in discontinuation rates was small, and the same factors were associated with statin discontinuation in people with and without AD. The findings suggest that cognitive decline plays a minor role on statin discontinuation.

Supplementary information

The online version contains supplementary material available at 10.1007/s00228-022-03320-3.

The changing pattern of statin use in people with dementia: A population-based study

BACKGROUND

After a dementia diagnosis, goals of care are often reassessed, including the use of preventive medications like statins.

OBJECTIVE

To examine changes in statin use after initiating medication for managing dementia.

METHODS

A case-crossover study utilizing medication dispensing data from the Australian Pharmaceutical Benefits Scheme (PBS) 10% random sample was conducted. Use of statins was compared in the 12 months pre- and post-initiation (pre-period and post-period) of anti-dementia medications or risperidone for behavioural symptoms of dementia. Individuals aged ≥65 years who had their first dispensing of anti-dementia medication or risperidone between July 2006 and June 2017 and survived ≥12 months after their first supply were included. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for change in statin use in the discordant pairs.

RESULTS

The cohort (n = 19,809) had a median age of 81 years and 61% were female. Statins were less likely to be used after initiating anti-dementia medication or risperidone (OR 0.50; 95%CI 0.45-0.55). The OR for statin use in the post-period versus the pre-period decreased annually over the 11 years from 1.21; 95%CI 0.84-1.75 in 2006-7 to 0.31; 95%CI 0.24-0.41 in 2016-17 (p for interaction <0.05).

CONCLUSION

Statins are more likely to be ceased than started after initiating medication for dementia. This may reflect changes in goals of care, or changes in the interpretation of the available evidence for the safety and efficacy of statins in older people living with dementia.

Non-Adherence to Statin Treatment in Older Patients with Peripheral Arterial Disease Depending on Persistence Status

The effectiveness of statins in secondary prevention of peripheral arterial disease (PAD) largely depends on patients’ adherence to treatment. The aims of our study were: (a) to analyze non-adherence during the whole follow-up in persistent patients, and only during persistence for non-persistent patients; (b) to identify factors associated with non-adherence separately among persistent and non-persistent patients. A cohort of 8330 statin users aged ≥65 years, in whom PAD was newly diagnosed between January 2012–December 2012, included 5353 patients persistent with statin treatment, and 2977 subjects who became non-persistent during the 5-year follow-up. Non-adherence was defined using the proportion of days covered <80%. Patient- and statin-related characteristics associated with non-adherence were identified with binary logistic regression. A significantly higher proportion of non-adherent patients was found among non-persistent patients compared to persistent subjects (43.6% vs. 29.6%; p < 0.001). Associated with non-adherence in both persistent and non-persistent patients was high intensity statin treatment, while in non-persistent patients, it was employment and increasing number of medications. In patients with a poor adherence during their persistent period, an increased risk for discontinuation may be expected. However, there is also non-adherence among persistent patients. There are differences in factors associated with non-adherence depending on patients’ persistence.

Patient-Associated Characteristics Influencing the Risk for Non-Persistence with Statins in Older Patients with Peripheral Arterial Disease

BACKGROUND AND OBJECTIVES

Secondary prevention of peripheral arterial disease includes administration of statins regardless of the patient's serum cholesterol level. Our study aimed to identify patient-associated risk factors for statin non-persistence and comparison of the explanatory power of models based on clusters of patient-associated characteristics.

METHODS

Our study cohort (n = 8330) was assembled from the database of the largest health insurance provider in the Slovak Republic. Statin users aged ≥ 65 years in whom peripheral arterial disease was diagnosed during 2012 were included. Patients were followed for 5 years; those with a treatment gap period of at least 6 months without statin prescription were classified as "non-persistent". The risk factors for non-persistence were identified within six models (sociodemographic, cardiovascular events, comorbid conditions, statin-related characteristics, cardiovascular co-medication and full model) using Cox regression. The explanatory power of models was assessed using Harrell's C-index.

RESULTS

At the end of the follow-up, 35.7% of patients were found to be non-persistent. The full model had the highest explanatory power (C = 0.632). Female sex, atorvastatin and rosuvastatin as initially administered statins, being a new statin user and an increasing co-payment were associated with an increased risk for non-persistence. Increasing age, history of ischaemic stroke, diabetes mellitus, general practitioner as index prescriber, increasing overall number of medications and co-administration of certain cardiovascular co-medications were associated with a lower likelihood for non-persistence.

CONCLUSIONS

Patients identified as high risk for non-persistence require special attention aimed at the improvement of their persistence with statin treatment.

Predictors of first-year nonadherence and discontinuation of statins among older adults: a retrospective cohort study

AIMS

The aim of this study was to examine the level of and predictors of statin nonadherence and discontinuation among older adults.

METHODS

Among 22 340 Australians aged ≥65 years who initiated statin therapy from January 2014 to December 2015, we estimated the first-year nonadherence (proportion of days covered [PDC] <0.80) and discontinuation (≥90 days without statin coverage) rates. Predictors of nonadherence and discontinuation were examined via multivariable logistic regression. Analyses were performed separately for general beneficiaries (with a higher co-payment; n = 4841) and concessional beneficiaries (with a lower co-payment; n = 17 499).

RESULTS

During the one-year follow-up, 55.1% were nonadherent (concessional 52.6%; general beneficiaries 64.2%) and 44.7% discontinued statins (concessional 43.1%; general beneficiaries 50.4%). Among concessional beneficiaries, those aged 75-84 years and ≥85 years were more likely to discontinue than people aged 65-74 years (odds ratio 1.11, 95% confidence interval 1.04-1.19 and 1.38, 1.23-1.54, respectively). Diabetes was associated with an increased likelihood of nonadherence and discontinuation, while hypertension, angina and congestive heart failure were associated with a lower likelihood of nonadherence and discontinuation. Anxiety was associated with an increased likelihood of discontinuation, but polypharmacy (concurrent use of five or more drugs) was associated with a lower likelihood of nonadherence and discontinuation. Statin initiation by a general medical practitioner was associated with both increased likelihood of nonadherence and discontinuation. Similar predictors of nonadherence and discontinuation were identified for the general beneficiaries.

CONCLUSIONS

Among older adults prescribed statins, first-year nonadherence and discontinuation are high. Specific population subgroups such as people aged ≥85 years, those with diabetes or anxiety may require additional attention to improve statin adherence.