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. 2026 Sep 8;63:101635. doi: 10.1016/j.lana.2026.101635

Hospital admissions for ambulatory care-sensitive conditions among people with gout and other crystal arthropathies in Alberta, Canada: a population-based matched cohort study

Dani G Contreras a, Claire EH Barber a,b, Cheryl Barnabe a,b,∗
PMCID: PMC13573183  PMID: 42741609

Summary

Background

Admissions for ambulatory care sensitive conditions (ACSCs) are used as an indicator of access and quality of care. Our aim was to estimate hospitalization rates for national indicator ACSCs in people with crystal arthropathies relative to the general population.

Methods

We conducted a population-based matched cohort study of persons with crystal arthropathies and age and sex-matched unexposed controls using administrative data from Alberta, Canada from years 2002–2023. We applied ICD-10-CA code-based case definitions for Canadian ACSCs. We calculated incidence rate ratios (IRRs) for any ACSC and each individual condition at 3 and 5 years after index date using zero-inflated Poisson regression modelling. We examined effects of sex, age, location of residence, and socioeconomic status on estimates.

Findings

There were 129,378 individuals meeting the case definition for crystal arthropathies. In cases 11.6% of all hospital admissions (n = 20,889/180,696) were for an ACSC, compared to 9.5% (n = 10,607/111,102) in matched unexposed. People with crystal arthropathies had an increased risk of an ACSC admission at 3 years (adjIRR 1.12, 95% CI, 1.05–1.18) and 5 years (adjIRR 1.14, 95% CI, 1.09–1.19) driven primarily by heart failure. Older age, rural residence and lower socioeconomic status were associated with increased admission rates.

Interpretation

Case status was associated with an increased risk of being hospitalized for ACSCs compared to the general population. Older age, rural residents, and those who experience material and social deprivation were at highest risk. High-quality care for disease and comorbidity management that is attentive to the social determinants of health is required to optimize care.

Funding

Canadian Institutes of Health Research.

Keywords: Acute care use, Health services research, Gout, Crystal arthropathies, Ambulatory care sensitive conditions, Preventable hospital admissions

Research in context.

Evidence before this study

Gout and calcium pyrophosphate disease (CPPD) are both crystal arthropathies, characterized by acute attacks of joint pain, swelling and stiffness, but with chronic attacks leading to disabling joint deformities. Gout frequently occurs in association with metabolic diseases, and can be a complication of the management of cardiac and renal diseases. CPPD is associated with electrolyte abnormalities and endocrine diseases. As these conditions are highly prevalent (3%–7% of the general population, varying by country) they are predominantly managed in primary care settings, supported by specialist care from rheumatologists as needed. Clinical experience suggested an increasing volume of emergency department visits and hospitalizations were related to crystal arthropathy flares, and with more admissions for other diagnoses such as cardiovascular events being complicated by crystal arthropathy flare. We conducted a review in EMBASE and Medline between January 2000 and January 2024 using search terms related to “gout” or “crystal arthritis”, and “emergency department” or “hospital”. We identified 12 studies presenting data on the epidemiology of all-cause emergency department use and hospitalization, and 34 studies presenting specific-cause visit analyses including incidence rates of gout flares and hospitalizations complicated by crystal arthropathy. Acute care use for crystal arthropathies is rising, likely reflecting issues of increasing frequency of associated conditions in society, but also deficits in access and provision of high quality care. In this submission, we describe hospital admissions by persons with gout and other crystal arthropathies, relative to the general population, for ambulatory care sensitive conditions (ACSCs) used in health system surveillance in Canada. ACSCs are indicators of ambulatory care access and quality; visits for these conditions (grand mal status and other epileptic convulsions; chronic lower respiratory diseases; asthma; diabetes; heart failure and pulmonary edema; hypertension; and angina) are considered preventable and avoidable should an individual have access to high quality healthcare. Prior to our study, only a study from Sweden had examined ACSC admissions in people with gout, finding a 41% increased rate of hospital admissions compared to persons without gout. We used linked datasets from 2002 to 2023 maintained by Alberta Health for the Alberta Health Care Insurance Plan (AHCIP) and Alberta Health Services, as a single-payer health system, to create age and sex matched case and control cohorts for our analysis to explore ACSCs as sources of acute care use.

Added value of this study

This study confirms an increased risk of ACSC hospitalizations in persons with gout and other crystal arthropathies in a universal healthcare setting. ACSC hospitalizations were predominantly driven by heart failure and pulmonary edema. Older age, rural residence and lower socioeconomic status were associated with increased admission rates.

Implications of all the available evidence

These results signal a need to intervene for health system appropriateness and efficiency, and quality of care. Potential targets to reduce avoidable acute care use include addressing comorbidities, patient education, collaboration between primary care and specialty care, and the implementation of novel models of care to optimize the management of crystal arthropathies.

Introduction

Gout and other crystal arthropathies are highly prevalent forms of inflammatory arthritis, affecting approximately 3% of the Canadian population but up to 7% of residents in other countries, with rising incidence and prevalence.1, 2, 3 In clinical practice, persons with crystal arthropathies are likely to require management of multiple competing conditions. Gout frequently occurs in association with metabolic diseases such as diabetes and hypertension,4 and acute attacks can be triggered by volume status shifts such as when diuresis is employed in the management of heart failure. Calcium pyrophosphate disease (CPPD) is associated with aging, previous joint injury, but also with particular electrolyte abnormalities (hypomagnesemia, hypophosphatasia), endocrine diseases (hyperparathyroidism, hypothyroidism, diabetes), hemochromatosis, genetic diseases, and also musculoskeletal diseases of osteoporosis and osteoarthritis.5 The majority of multimorbidity care is facilitated and delivered in primary care settings, supported by specialist care as required. However, increasing acute care utilization characterized by emergency visits and hospital admissions in persons with gout and other crystal arthropathies has been observed.2 This may reflect several factors, including suboptimal patient education about their condition and difficulties with treatment adherence,6 but also insufficient access to providers and high quality care.

In health system access and care quality surveillance, a set of conditions termed ‘Ambulatory Care Sensitive Conditions’ (ACSCs) are used as indicators of access to high quality primary care.7 Hospitalizations for ACSC conditions are reduced when elements of this high quality primary care, such as continuity of care, are available.8 Jurisdictions monitoring health system quality select their own individual ACSCs.9 In Canada, admission rates for seven conditions are monitored: grand mal status and other epileptic convulsions; chronic lower respiratory diseases; asthma; diabetes; heart failure and pulmonary edema; hypertension; and angina.7 High rates of hospitalizations for the conditions overlapping with crystal arthropathy comorbidities may indicate insufficient access to primary care overall, and also reflect suboptimal crystal arthropathy management leading to the development of comorbidities.

The aim of this study was to estimate hospitalization rates for these Canadian ACSC indicators in people with a diagnosis of crystal arthropathies relative to the general population. Identifying excess hospitalizations in persons with crystal arthropathy would demonstrate the need for health service enhancements to reduce acute care use.

Methods

Study design

We created a retrospective cohort of persons with crystal arthropathies using population-level administrative data. In Alberta (population ∼5 million), all health administrative data are maintained by Alberta Health for the Alberta Health Care Insurance Plan (AHCIP) and Alberta Health Services, as a single-payer health system. The administrative data sets represent patient interactions with the health care system at all sources (ambulatory care with primary care physicians and specialists, emergency department and urgent care use, and hospital admissions). Linkage for cohort creation and outcome ascertainment is made possible through a Unique Lifetime Identifier assigned to each patient.

Datasets

For this project, three data sets were accessed: Discharge Abstract Database (hospitalizations, April 2007 to March 2023), Practitioner Claims (outpatient physician visits, April 2002 to March 2023), and Provincial Registry (demographic information, April 2002 to March 2023).

Participants

All individuals registered with the AHCIP beginning in fiscal year 2002–2003 up until the study end date of March 31, 2023, were considered for inclusion. Individuals with gout and crystal arthropathies were included in the cohort if they met the case definitions derived from an algorithm with diagnostic codes from the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM; 274.X, 712.X) for Practitioner Claims or ICD-10-CA (M10.X, M11.X) for Discharge Abstract Database. Those included in the cohort must have one or more hospitalization or at least two physician claims within five years but at least one day apart.10 This case definition is used by the Canadian Chronic Disease Surveillance System for surveillance of gout and other crystal arthropathies. There was a five-year washout period from the study start date or an individual’s registration with the AHCIP to exclude prevalent exposed.

We excluded individuals younger than 18 years of age and those meeting case definitions of other inflammatory arthritis conditions of rheumatoid arthritis (M05.X-M06.X), psoriatic arthritis (696.X, 720.X, L40.X, M07.0, M07.1, M07.2, M07.3, and M45.X), and axial spondyloarthritis (720.X and M45.X). The unexposed were randomly selected among all eligible persons in Alberta enrolled in the AHCIP. We employed control matching based on age (within 5 years) and sex in a 1:1 ratio. The index date for the exposed to determine the beginning of the follow-up period was the date of the first crystal arthropathy diagnosis code, and this same calendar date was applied as the index date for their matched unexposed.

Outcomes

The primary outcome of this study was hospitalization rates for any ACSC, and each individual condition, calculated as incidence rate ratios (IRRs) (95% confidence intervals [CIs]) for exposed relative to unexposed. The exposed and unexposed were observed for 3 and 5 years from their index dates, with the follow-up period being between 2007 and 2023. We applied the defining ICD-10-CA codes for each ACSC following CIHI methodology.7 (see Supplementary Material Table 1). Various factors influencing admission rates were included, such as age (continuous), sex (male or female as recorded in administrative data), location of residence (rural or urban, based on postal code), socioeconomic status. Socioeconomic status (SES) was derived from the Pampalon deprivation index,11 and cross-tabulated the quintiles to create a combined total deprivation index, based on the 2021 Material and social deprivation index created by Institut national de santé publique du Québec (see Supplementary Material Fig. 1),12 and the presence of comorbid conditions that are not ACSCs (binary, yes/no), as per the list developed by Charlson and modified by Quan.13,14

Statistical analyses

Descriptive statistics were used to report the characteristics of ACSC hospitalizations from 2007 to 2023 for exposed and unexposed. The IRR for any ACSC and each individual condition was calculated for the exposed and unexposed. For this outcome, all hospitalizations for ACSCs were included in the numerator, including instances of repeated hospitalizations by an individual, from the index date out to three and five years. IRRs (95% CIs) for each ACSC were calculated using a zero-inflated Poisson regression model. Poisson regression is a generalized linear model used to model count variables (e.g., number of ACSC hospitalizations three and five years from the index date) in which there is an excess of zeros (i.e., most had no hospitalization for any ACSC or have no hospitalization at all). The significance of the coefficients in the regression model was determined using a two-sided Wald test. We note that for socioeconomic status, data missingness is ∼8% (n = 24,134/291,798 hospital encounters). Missing values were imputed using multiple imputation by chained equations,15 with 5 generated datasets.

To present population-specific estimates, we also completed a stratified analysis by sex, age groups (≤40 years old, 41–60 years old, ≥61 years old), location of residence, SES, and presence of comorbidities not considered ACSCs (binary, yes/no). We reported IRRs 5 years from index date.

Statistical analyses were performed using R version 4.4.0 packages pscl16 for zero-inflated Poisson regression.

Ethics

Ethics approval for this study was provided by the University of Calgary Conjoint Health Research Board (ethics ID REB22-1316), with a waiver of individual consent granted by Alberta Health Services.

Role of the funding source

The funders of the study had no role in study design, data collection, data analysis, data interpretation, writing of the report, or the decision to submit the paper for publication.

Results

Cohort demographics

From 2007 to 2023, there were 129,378 individuals meeting the case definition for crystal arthropathies (Table 1). Of these, 42.6% (n = 55,085/129,378) of the individuals with crystal arthropathies had a hospital admission for any reason after their index date, compared to only 31.2% (n = 40,373/129,378) of individuals in the control population. Of hospitalizations, 66.1% of people with crystal arthropathies (n = 119,352/180,696) and 72.1% of people without crystal arthropathies (n = 80,083/111,102) were male. The mean age at admission in the exposed was 71 years (SD 15) and 74 years (SD 14) in the unexposed. Over three-fourths of the hospital visits for both exposed and unexposed were made by people living in urban areas. Demographic characteristics of exposed and unexposed individuals with at least 1 hospitalization are available in Supplementary Material Table 2.

Table 1.

Cohort characteristics of hospital separations of persons with gout and other crystal arthropathies, and unexposed, from 2007 to 2023.

Characteristic N (%) unless otherwise indicated
Exposed Unexposed
Individuals 129,378 129,378
Individuals with any hospital separationa 55,085 (42.6) 40,373 (31.2)
Unique hospitalizations, any cause 180,696 111,102
 Sex
 Female 61,344 (33.9) 31,019 (27.9)
 Male 119,352 (66.1) 80,083 (72.1)
 Age at admission
 Mean (SD) 71.4 (14.5) 73.6 (13.7)
 Median (IQR) 73 (62, 82) 76 (65, 84)
 Location of Primary Residence
 Rural 38,524 (21.3) 23,420 (21.1)
 Urban 142,172 (78.7) 87,682 (78.9)
 Comorbidities 118,548 (65.7) 61,571 (55.7)
 Unknown 209 556
 Pampalon Deprivation Index
 T1—Materially and socially privileged DA 21,731 (12.0) 14,187 (12.8)
 T2—DA with a tendency towards privilege 24,907 (13.8) 15,583 (14.0)
 T3—DA privileged on one dimension but deprived on the other 32,596 (18.0) 20,309 (18.3)
 T4—DA with a tendency towards deprivation 40,054 (22.2) 23,834 (21.4)
 T5—Materially and socially deprived DA 61,408 (34.0) 37,189 (33.5)
ACSC Hospitalizations, Overallb 20,889 (11.6) 10,607 (9.5)
Individual cause ACSC hospitalizations
 Grand Mal status and other epileptic convulsions 428 (2.0) 367 (3.5)
 Chronic lower respiratory diseases 6467 (31.0) 4601 (43.4)
 Asthma 204 (1.0) 81 (0.8)
 Diabetes 1146 (5.5) 686 (6.5)
 Heart failure and pulmonary edema 10,558 (50.5) 3670 (34.6)
 Hypertension 639 (3.1) 321 (3.0)
 Angina 1447 (6.9) 881 (8.3)
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All variables (sex, age at admission, location of primary residence, ACSC hospitalizations, and socioeconomic status) show n(%) of each unique hospital separation, not at the individual level.

DA: Dissemination Area.

a

Individuals with hospital separations: the proportion is the number of individuals with a hospitalization over the total number of individuals in the cohort.

b

The proportion of unique ACSC hospitalizations over the total number of unique hospitalizations from 2007 to 2023.

Hospital admissions for ACSCs

Overall, 11.6% of all hospitalizations by people with crystal arthropathies (n = 20,889/180,696) were for an ACSC, compared to 9.5% in people without crystal arthropathies (n = 10,607/111,102) (Table 1). Of individual conditions, heart failure and pulmonary edema admissions accounted for 5.8% of the total hospitalizations (n = 10,558/180,696), and 50.5% of the ACSC admissions (n = 10,558/20,889) in persons with crystal arthropathies, compared to 3.3% (n = 3670/111,102) and 34.6% (n = 3670/10,607) in unexposed respectively. The next most common individual condition hospitalizations were for chronic lower respiratory diseases, comprising 4% of overall hospitalizations without significant differences between those with (n = 6467/180,696) and without (n = 4601/111,102) crystal arthropathies.

Incidence rate ratios of preventable hospitalizations

For any ACSC admission, people with crystal arthropathies had a 13% higher crude rate of hospitalizations compared to those without crystal arthropathies three years from their index date (IRR 1.13, 95%CI 1.07, 1.20), which increased to 16% five years from the index date (IRR 1.16, 95%CI 1.11, 1.21) (Table 2). After adjusting for age, sex, location of residence, socioeconomic status, and comorbidities, the risk for an ACSC admission remained higher among those with crystal arthropathies, increased by 12% at 3 years (1.12, 95% CI 1.05, 1.18) and 14% at 5 years (IRR 1.14, 95% CI1.09, 1.19). Among individual ACSCs, hospitalization rates for heart failure and pulmonary edema remained consistently high among those with crystal arthropathies compared to those without crystal arthropathies, even after adjusting for potential confounders. Three years from the index date, people with crystal arthropathies had a 23% higher risk of being hospitalized (adjusted IRR 1.23, 95% CI 1.11, 1.37), which increased to 30% higher (adjusted IRR 1.30, 95% CI 1.20, 1.41) at five years after the index date.

Table 2.

Incidence rate ratios (95% CI) of hospitalizations for ambulatory care sensitive conditions (ACSCs), exposed with gout and other crystal arthropathies, relative to unexposed.

Ambulatory care sensitive condition 3 years from index date
 5 years from index date
Unadjusted Adjusteda Unadjusted Adjusteda
Overall 1.13 (1.07, 1.20) 1.12 (1.05, 1.18) 1.16 (1.11, 1.21) 1.14 (1.09, 1.19)
Grand Mal Seizures 1.33 (0.85, 2.09) 1.05 (0.68, 1.62) 1.10 (0.78, 1.55) 0.97 (0.68, 1.38)
Chronic lower respiratory diseases 0.84 (0.77, 0.92) 0.85 (0.78, 0.93) 0.90 (0.84, 0.96) 0.89 (0.83, 0.95)
Asthma 2.29 (0.67, 7.74) 0.66 (0.32, 1.37) 2.67 (1.05, 6.77) 2.08 (0.75, 5.79)
Diabetes 0.78 (0.57, 1.07) 0.80 (0.59, 1.09) 0.93 (0.73, 1.18) 0.80 (0.62, 1.02)
Heart failure and pulmonary edema 1.30 (1.17, 1.44) 1.23 (1.11, 1.37) 1.36 (1.26, 1.48) 1.30 (1.20, 1.41)
Hypertension 1.14 (0.54, 2.42) 1.08 (0.55, 2.13) 1.31 (0.72, 2.40) 1.03 (0.56, 1.89)
Angina 1.25 (0.86, 1.81) 1.27 (0.86, 1.86) 1.12 (0.85, 1.48) 1.09 (0.83, 1.45)
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a

Adjusted for age, sex, location of residence, and socioeconomic status (using Pampalon deprivation index matrix), and presence of comorbidities that are not ACSCs.

Population-specific estimates

We found no significant differences in the rates of hospitalizations between males and females with crystal arthropathies for all ACSCs combined (Fig. 1). For specific ACSCs, we found males with crystal arthropathies had higher rates of hospitalizations for chronic lower respiratory diseases compared to female exposed (IRR 1.25, 95% CI 1.14, 1.38). Males had approximately a 75% lower rate of hospitalizations for hypertension compared to females (IRR 0.25, 95% CI 0.08, 0.83). People aged 61 and older had an 36% higher rate of ACSC hospitalizations compared to those 40 years and under (IRR 1.36, 95%CI 1.06, 1.76). Those in rural areas also had a 18% higher rate of hospitalizations compared to those in urban locations (IRR 1.18, 95%CI 1.11, 1.25). Those with comorbid conditions had a 46% higher rate of ACSC hospitalizations compared to those without (IRR 1.46, 95% CI 1.36, 1.56). Compared to people with crystal arthropathies who were materially and socially privileged (SES 1), people with lower SES had higher rates of ACSC hospitalizations, with up to 25% higher rates in people in SES 5 (IRR 1.25, 95%CI 1.14, 1.37). The IRR for each ACSC condition is shown in Supplementary Material Table 3.

Fig. 1.

Fig. 1

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Incidence rate ratios (95% CI) for all ACSCs combined among exposed group.

Discussion

This study provides new context to our understanding of healthcare utilization by people with crystal arthropathies in Canada. In this population-based cohort, approximately 1 in 10 admissions were for a condition sensitive to ambulatory care quality. The risk for an ACSC admission was elevated 12% at three years and 14% at five years after the date of diagnosis in persons with crystal arthropathy compared to matched unexposed from the general population. This was primarily driven by hospital admissions for heart failure and pulmonary edema, in which people with crystal arthropathies have a 34% higher risk of being hospitalized compared to those without crystal arthropathies within five years after diagnosis. An unexpected finding was that of chronic lower respiratory disease emerging as a higher risk for admission in men and those of low socioeconomic status with crystal arthropathy. To our knowledge, there are no studies examining direct associations between crystal arthropathies and chronic lower respiratory diseases. A cross-sectional study conducted in patients with chronic obstructive pulmonary disease (COPD) in Germany found that uric acid was associated with decreased lung function, more COPD exacerbations, and cardiovascular comorbidities.17 There is also emerging evidence on the influence of air pollution on developing gout,18,19 and gout flares.20,21 Due to the limitations of administrative data, we did not have information on urate levels and were unable to control for these in the models.

As access to healthcare is an important determinant of health utilization and is influenced by many potential factors, we investigated the effect of sex, location of residence, age, and socioeconomic status on the rates of ACSC hospitalizations among people with crystal arthropathies. Older individuals, rural residents and those with increasing social and material resource deprivation all incurred a higher risk for an ACSC admission. In Canada, people aged 60 and older had 2–3 increase in odds of an ACSC admission compared to people aged 21–40 years.22 Additionally, among older adults in the United States, rural Medicare beneficiaries had higher rates of emergency department ACSCs compared to urban Medicare beneficiaries.23 In other research, persons with lower levels of socioeconomic status have similarly been documented to have higher rates of ACSC hospitalizations,7,24 although with some studies with discrepant results.25 The mechanisms by which socioeconomic status impact ACSC admissions could include a higher burden of disease and comorbidities and lower access to after-hours care.26,27

While hospitalizations for ACSCs have been rarely studied in the rheumatology context, our findings are consistent with those reported in a study from Sweden which also estimated risk for admissions in a gout cohort.25 In that study, 16% of people with gout had an ACSC hospitalization compared to 9% in controls in their matched analysis from 1998 to 2005.25 People with gout had a 41% higher risk for ACSC hospitalizations compared to those without gout, also driven by the risk for an admission for heart failure. Other studies conducted in other forms of inflammatory arthritis similarly highlight an increased risk for ACSC admissions in case populations relative to controls. This ranges from 5.5% higher odds of preventable hospitalizations in Taiwanese people with axial spondyloarthritis 3 months after being prescribed low-dose corticosteroids,28 to a moderate 14% increased risk of admissions in the 5 years after diagnosis in RA in the same healthcare setting as described in this current study,29 and up to a 61% higher risk of ACSC hospitalizations five years before and after RA diagnosis compared to people without RA in Taiwan.30

As high-quality primary healthcare access is protective against ACSC hospitalizations, our findings speak to the critical nature of securing appropriate resources for populations at highest risk of a negative outcome. This is increasingly challenging in healthcare settings facing constraints on human personnel and budgets to support primary care. Specialty care settings are also facing pressures, limiting the opportunities for primary care and specialty care interactions to optimize inflammatory disease and comorbidity management.31, 32, 33 Given these realities, it may be best to focus attention on the comorbidities that represent the highest burden in people with gout, and which are driving avoidable acute care use to the highest degree. Heart failure and pulmonary edema is a clear target, being amongst the most common reason for hospitalizations in Canada,34 with known higher prevalence in those with gout,35,36 with the treatment of exacerbations of heart failure increasing gout flares, and on the other hand gout management worsening heart failure.37 Previous literature has shown an association between gout and cardiovascular diseases and mortality.35,38 A study in 2022 showed an increase in risk of cardiovascular events after gout flares.39 This may be attributed to chronic inflammation associated with inflammatory arthritis conditions.

In the management of gout and other comorbidities, patient education and counselling are proposed as having a role in managing symptoms, minimizing flares, and ultimately preventing avoidable acute care use. The American College of Rheumatology and European Alliance of Associations for Rheumatology highly recommend patient education and shared decision-making to be integrated into routine clinical care, where possible.40,41 Primary care providers are usually the patient’s first point of contact in the healthcare system, and most of the crystal arthropathy exposed are managed in primary care settings. The rheumatology community thus needs to offer better education and support for the primary care providers to apply treat-to-target algorithms, screen for comorbidities, and monitor disease. In Alberta, there is a Specialist Link resource that connects primary care providers with specialists, providing tele-advice line and clinical care pathways for many conditions, including gout,42 but it is unknown how widely adopted this is in practice. Primary care providers are strongly advised to screen for comorbidities such as renal impairment and cardiovascular diseases.42 There is evidence that screening for multimorbidities in people with rheumatic diseases resulted in fewer ED visits and hospitalizations.43 The role of other medical specialties in diagnosing and managing gout is also vital. Noting the high prevalence of cardiovascular and kidney disease in people with gout, collaborative care with cardiologists and nephrologists may be optimized to monitor and improve gout outcomes in patients.

Other models of care have also considered the combined role of rheumatology and other medical specialists and allied health professionals in the care and management of gout. Multiple studies have shown improved gout care can be achieved through shared and multidisciplinary care.44,45 An evaluation of a multidisciplinary, nurse-led treatment protocol in Canada reached the target serum uric acid (sUA) target at 6 months.44 Pharmacists also have a key role in treatment initiation and monitoring sUA levels in people with gout and adjusting treatment if needed.46 Improved gout management may in turn reduce heart failure admissions and death,47 major adverse cardiovascular events,48 It may also be beneficial to leverage existing electronic medical records alert systems to identify people with gout who present to EDs and/or are admitted to hospital for prioritization of consultation. A recent study by Jackson et al. identified people who present to EDs with a gout flare alert,49 and subsequently found that approximately only 35% of those had an outpatient visit addressing their gout.50 Additionally, the patients did not receive the standard first-line treatment for gout while in ED, which may have unintended consequences in the future. Implementing this gout flare alert and following patients prospectively may be helpful in optimizing outcomes. To minimize exacerbations of comorbid conditions, it is important to ensure that gout is well-controlled.

This study contributes new knowledge on healthcare utilization outcomes in people with crystal arthropathies in a health system with universal access to health care. Strengths include the population-based nature of our dataset, and the use of established and validated Canadian-indicator ACSCs from CIHI for outcome determination.7 Our study also has limitations. The data stewards created the case and control cohorts using the Canadian Chronic Disease Surveillance System methodology, and did not designate which type of crystal arthropathy each case met the definition for. Given the nature of administrative data with limitations in data completeness and content of data sets51 we were unable to include important variables that may better help elucidate the nature of primary care access and ACSC hospitalizations. Variables that could inform understanding of an individual’s gout management and thus influences on particular admissions such as those for cardiovascular events, such as uric acid levels and exposure to urate-lowering therapy, were not available. We conducted several subgroup analyses, which increases the probability of Type I errors. The role of specialist management in complicated crystal arthropathies was also not considered. Additionally, equity factors such as gender and ethnic identities are not routinely collected data. Other indicators of socioeconomic status, such as educational attainment and annual income may be better proxies than area-level deprivation.

Conclusion

People with crystal arthropathies have an increased risk of being hospitalized for avoidable conditions compared to those without crystal arthropathies. This was driven by hospitalizations for heart failure and pulmonary edema. This highlights the gap in care for people with crystal arthropathies, emphasizing the importance of timely diagnosis, initiation of treatment, and screening for comorbidities, especially cardiovascular conditions.

Contributors

The study was conceptualized by CB. CEHB and CB were responsible for securing funding for this project. All authors contributed to study design. DG completed the analysis of raw data under the supervision of CB and CB and CEHB verified the data and analysis. All authors participated in interpretation of results. DG drafted the manuscript and all authors contributed to writing and revisions. All authors read and approved the final manuscript. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.

Data sharing statement

Data access agreements with Alberta Health do not permit data sharing with outside entities.

Use of artificial intelligence

Not used.

Declaration of interests

We declare no competing interests.

Acknowledgements

Funding was from the Canadian Institutes of Health Research Funding Reference Number MHM185632; Canada Research Chair in Rheumatoid Arthritis and Autoimmune Diseases (Barnabe).

Footnotes

Appendix A

Supplementary data related to this article can be found at https://doi.org/10.1016/j.lana.2026.101635.

Appendix A. Supplementary data

Supplementary Material Fig. S1 and Tables S1–S3
mmc1.pdf (222.8KB, pdf)

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Supplementary Materials

Supplementary Material Fig. S1 and Tables S1–S3
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