Multimorbidity in Australia: Comparing estimates derived using administrative data sources and survey data

Abstract

BackgroundEstimating multimorbidity (presence of two or more chronic conditions) using administrative data is becoming increasingly common. We investigated (1) the concordance of identification of chronic conditions and multimorbidity using self-report survey and administrative datasets; (2) characteristics of people with multimorbidity ascertained using different data sources; and (3) whether the same individuals are classified as multimorbid using different data sources.MethodsBaseline survey data for 90,352 participants of the 45 and Up Study—a cohort study of residents of New South Wales, Australia, aged 45 years and over—were linked to prior two-year pharmaceutical claims and hospital admission records. Concordance of eight self-report chronic conditions (reference) with claims and hospital data were examined using sensitivity (Sn), positive predictive value (PPV), and kappa (κ).The characteristics of people classified as multimorbid were compared using logistic regression modelling.ResultsAgreement was found to be highest for diabetes in both hospital and claims data (κ = 0.79, 0.78; Sn = 79%, 72%; PPV = 86%, 90%). The prevalence of multimorbidity was highest using self-report data (37.4%), followed by claims data (36.1%) and hospital data (19.3%). Combining all three datasets identified a total of 46 683 (52%) people with multimorbidity, with half of these identified using a single dataset only, and up to 20% identified on all three datasets. Characteristics of persons with and without multimorbidity were generally similar. However, the age gradient was more pronounced and people speaking a language other than English at home were more likely to be identified as multimorbid by administrative data.ConclusionsDifferent individuals, with different combinations of conditions, are identified as multimorbid when different data sources are used. As such, caution should be applied when ascertaining morbidity from a single data source as the agreement between self-report and administrative data is generally poor. Future multimorbidity research exploring specific disease combinations and clusters of diseases that commonly co-occur, rather than a simple disease count, is likely to provide more useful insights into the complex care needs of individuals with multiple chronic conditions.

Epidemiology of multimorbidity in New Zealand: a cross-sectional study using national-level hospital and pharmaceutical data

“…A regional Australian study from New South Wales of adults aged 45 and over found prevalence of 36.1%–37.4%, based on pharmaceutical claims data and survey data, respectively; and a prevalence of 19.3% based on past hospital discharge data. 19 Restricting our own data to ages 45 and above returned a prevalence of 42.2% based on pharmaceutical dispensing data, and 13.1% based on hospital discharge data (not shown).…”

“… 45 A recent Australian study that linked survey data (for ages 45 plus) with routine pharmaceutical and hospitalisation data returned comparable prevalence estimates between survey and pharmaceutical data sources (37.4% and 36.1%), which were both around 17% points higher than prevalence estimated using hospital data (19.3%). 19 …”

“…There have been many prevalence studies of multimorbidity, as described in several systematic reviews. 2 3 12 13 Studies have generally focused on multimorbidity in specific populations (eg, the elderly 17 18 or among hospitalised patients 18 ); examined the general population, either among registered populations using existing patient databases 19 20 or using surveys of the general population 15 ; or have measured multimorbidity during primary care interactions. 21 …”

<p>Multimorbidity by Patient and Tumor Factors and Time-to-Surgery Among Colorectal Cancer Patients in Spain: A Population-Based Study</p>

“…4 Comorbidity describes a long-term health condition or disorder occurring alongside the primary disease of interest, such as cancer, 5 whereas multimorbidity refers to the existence of two or more comorbid conditions. 6 Comorbidity and multimorbidity are increasingly seen as a problem of the elderly but have also been increasingly reported at a younger age in patients with lower socioeconomic status. 7,8 Despite the common coexistence of comorbidity and cancer, the guidelines and delivery of cancer care generally focus on single disease management.…”

The pattern of Comorbidities and Associated Risk Factors among Colorectal Cancer Patients in Spain: CoMCoR study

“…Comorbidity describes the existence of a long-term health condition or disorder in the presence of a primary disease of interest, such as cancer [4], whereas multimorbidity refers to the existence of more than one comorbid condition [5]. Comorbidity and multimorbidity are increasingly seen as a problem of the elderly, but have also been reported as occurring more often and at a younger age in patients of lower socioeconomic status [6,7].…”