Measuring multimorbidity using Australian linked administrative health data sources

The growing number of individuals living with multimorbidity – the presence of two or more chronic conditions – is a challenge facing many healthcare systems internationally. Multimorbidity has been hailed a priority for research and practice, but Australian studies of multimorbidity are impeded by the lack of national primary care data, data silos, researcher access to data, and limited information contained within the data that are available. This thesis demonstrates how data linkage can be used to enhance the understanding of multimorbidity and its outcomes via a series of studies using Australian linked data sources, including claims-based, cohort study and clinical registry datasets for residents of NSW, Australia's most populous state. Thesis studies found variations in the recording of common health conditions between hospitals, under ascertainment of multimorbidity in administrative data, and differences in the estimates of multimorbidity dependent on the data used. Thesis studies also showed we can enhance our understanding of multimorbidity by exploring related concepts of patient risk and complexity. Within administrative hospital inpatient data, one-third of hospitalised patients had both multimorbidity and elevated risks of frailty – and these patients had worse outcomes than those with one or neither factor. The addition of clinical registry data also improved risk adjustment for hospital readmission performance indicators for total knee and hip replacement over and above models including multimorbidity measured using administrative hospital inpatient data. The research presented here highlights the benefits of the use of linked data in Australian multimorbidity research in three ways. Firstly, it underlines the need for incorporation of chronic disease information from multiple databases, including self-reported, inpatient, and claims-based data to accurately capture the extent of chronic disease and to identify people with multimorbidity. Secondly, it emphasises the need to examine complexities in the interplay between drivers of adverse outcomes – including multimorbidity, frailty and clinical assessment of a patient's overall health – in identifying patients with increased risk of complications and informing future hospital resource planning. And thirdly, it demonstrates the value of integrating new data sources, such as clinical registries with linked administrative data for improving risk-adjustment of hospital performance measures

Evaluating the role of COPD in patients with heart failure using multiple electronic health data sources

Heart failure (HF) and COPD frequently co-exist. Shared symptoms and risk factors make diagnosis and management difficult and current understanding of the relationship between the diseases is limited. I used several electronic healthcare record (EHR) data sources, from the United States (US) and the United Kingdom (UK) to evaluate the impact of COPD on outcomes in patients with HF. First, I aimed to demonstrate that comorbidity data from EHR can be used to derive meaningful clusters in patients with chronic HF, expecting COPD to be a main driver of this phenotyping endeavour. Second, I compared outcomes (hospitalisation, mortality, healthcare utilisation) in patients with COPD-HF, between left ventricular ejection fraction (LVEF) groups. Third, I pooled data from previously published studies to assess the overall effect of HF management (beta-blockers) on outcomes in COPD. In a fourth study I examined whether COPD was associated with in-hospital mortality and management of patients hospitalised for HF and assessed association with LVEF. Lastly, I investigated whether COPD affected readmission in a population of patients hospitalised for HF. This work provides evidence to suggest that while COPD may not play a major role in determining a HF classification system based on comorbidities only, it affects clinical outcomes in the long-term, particularly for chronic HFpEF patients. Conversely, HF management such as beta-blockers does not appear to worsen outcomes in COPD patients. In the acute setting, coexisting COPD is independently associated with increased in-hospital mortality and decreased HF medication prescription and access to healthcare services amongst patients who survived their first HF admission. Readmission risk is higher amongst those with HF and COPD compared with HF-alone, though the most frequent reason for returning to hospital is still due to a cardiovascular cause.Open Acces

Vitamins C and D

The global coronavirus pandemic has highlighted the paramount importance of immune health and the nutrient status of peoples worldwide. Vitamins C and D have important roles in both the innate and adaptive immune systems and are known to support healthy immune function. Both vitamins C and D have gene regulatory roles with the ability to up- and down-regulate thousands of genes, thus playing pleotropic roles in human health and disease. People from low- and middle-income countries tend to have inadequate micronutrient intakes and status, as do specific subgroups from high-income countries. This can affect their resistance to both communicable and non-communicable diseases and the severity of these diseases. In this Special Issue, we have compiled review articles and research papers (both observational and interventional studies) that explore the role of vitamins C and D in numerous aspects of global and population health

Describing diversity of real world data sources in pharmacoepidemiologic studies: The DIVERSE scoping review

PURPOSE: Real-world evidence (RWE) is increasingly used for medical regulatory decisions, yet concerns persist regarding its reproducibility and hence validity. This study addresses reproducibility challenges associated with diversity across real-world data sources (RWDS) repurposed for secondary use in pharmacoepidemiologic studies. Our aims were to identify, describe and characterize practices, recommendations and tools for collecting and reporting diversity across RWDSs, and explore how leveraging diversity could improve the quality of evidence. METHODS: In a preliminary phase, keywords for a literature search and selection tool were designed using a set of documents considered to be key by the coauthors. Next, a systematic search was conducted up to December 2021. The resulting documents were screened based on titles and abstracts, then based on full texts using the selection tool. Selected documents were reviewed to extract information on topics related to collecting and reporting RWDS diversity. A content analysis of the topics identified explicit and latent themes. RESULTS: Across the 91 selected documents, 12 topics were identified: 9 dimensions used to describe RWDS (organization accessing the data source, data originator, prompt, inclusion of population, content, data dictionary, time span, healthcare system and culture, and data quality), tools to summarize such dimensions, challenges, and opportunities arising from diversity. Thirty-six themes were identified within the dimensions. Opportunities arising from data diversity included multiple imputation and standardization. CONCLUSIONS: The dimensions identified across a large number of publications lay the foundation for formal guidance on reporting diversity of data sources to facilitate interpretation and enhance replicability and validity of RWE

Nutrition, Diet and Healthy Aging

Over the last 100 years, the numerous advances in science, the improved sanitary conditions and a decline in poverty have led to an increase in life expectancy. As a result, in the coming years, the number of over-65s will triple, and the over-80s will be the fastest growing portion of the population.However, an increased lifespan is associated with an increase in chronic diseases, such as cardiovascular disease, diabetes, cancer, sarcopenia, and degenerative disorders. Therefore, ideally, increased lifespan should be associated to a better healthspan, which is the period one individual is living in good health.Based on evidence that aging is a multifaceted phenomenon, resulting from one or more failures at the molecular, cellular, physiologic, and functional levels, age-related diseases are difficult therapeutic targets.Data on the correlation between the quality of one’s diet and life expectancy, and the application of calorie restriction regimens, or of micronutrients, antioxidants and functional foods in the diet make nutrition, together with exercise, a natural weapon to combat age-related diseases and improve healthspan