Phase Specific Health Care Costs Associated with Giant Cell Arteritis in Ontario, Canada

OBJECTIVE

To estimate the additional health care system costs associated with giant cell arteritis (GCA) in the year pre-diagnosis, post diagnosis, and over long-term follow up compared to individuals with similar demographics and comorbidities without GCA.

METHODS

We performed a population-based study using health administrative data. Newly diagnosed cases of GCA (between 2002 and 2017 and ages 66 years and older) were identified using a validated algorithm and matched 1:6 to comparators using propensity scores. Follow up data was accrued until death, outmigration, or March 31, 2020. The costs associated with care were determined across three phases: the year before the diagnosis of GCA, the year after, and ongoing costs thereafter.

RESULTS

The cohort consisted of 6,730 cases of GCA and 40,380 matched non-GCA comparators. The average age was 77 years (interquartile range 72-82) and 68.2% were female. A diagnosis of GCA was associated with an increased cost of $6,619.4 (95% CI 5,964.9 - 7274.0) per patient during the 1-year pre-diagnostic period; $12,150.3 (95% CI 11,233.1 - 13,067.6) per patient in the 1-year post-diagnostic phase, and $20,886.2 (95% CI 17,195.2 - 24,577.2) per patient during ongoing care for year 3 onwards. Increased costs were driven by inpatient hospitalizations, physician services, hospital outpatient clinic services, and emergency department visits.

CONCLUSION

A diagnosis of GCA was associated with increased health care costs during all three phases of care. Given the substantial economic burden, strategies to reduce the healthcare utilization and costs associated with GCA are warranted.

High prevalence of comorbidities at diagnosis in immigrants with multiple sclerosis

Background:

Multiple sclerosis (MS) has been associated with certain comorbidities in general population studies, but it is unknown how comorbidity may affect immigrants with MS.

Objective:

To compare prevalence of comorbidities in immigrants and long-term residents at MS diagnosis, and in matched control populations without MS.

Methods:

We identified incident MS cases using a validated definition applied to health administrative data in Ontario, Canada, from 1994 to 2017, and categorized them as immigrants or long-term residents. Immigrants and long-term residents without MS (controls) were matched to MS cases 3:1 on sex, age, and geography.

Results:

There were 1534 immigrants and 23,731 long-term residents with MS matched with 4585 and 71,193 controls, respectively. Chronic obstructive pulmonary disease (COPD), diabetes, hypertension, ischemic heart disease, migraine, epilepsy, mood/anxiety disorders, schizophrenia, inflammatory bowel disease (IBD), and rheumatoid arthritis were significantly more prevalent among immigrants with MS compared to their controls. Prevalence of these conditions was generally similar comparing immigrants to long-term residents with MS, although COPD, epilepsy, IBD, and mood/anxiety disorders were less prevalent in immigrants.

Conclusion:

Immigrants have a high prevalence of multiple comorbidities at MS diagnosis despite the “healthy immigrant effect.” Clinicians should pay close attention to identification and management of comorbidity in immigrants with MS.

SAT0252 INCREASED MORTALITY FOR INDIVIDUALS WITH GIANT CELL ARTERITIS: A POPULATION-BASED STUDY

Background:

Individuals with giant cell arteritis (GCA) are at increased risk of serious morbidity including cardiovascular disease and stroke. Yet the risk of mortality among individuals with GCA have produced conflicting reports1.

Objectives:

Our aim was to evaluate excess all-cause mortality among individuals with GCA relative to the general population over time.

Methods:

We performed a population-based study in Ontario, Canada, using health administrative data among all individuals 50 years and older. Individuals with GCA were identified using a validated case definition (81% PPV, 100% specificity). All Ontario residents aged 50 and above who do not have GCA served as the General Population comparators. Deaths occurring in each cohort each year were ascertained from vital statistics. Annual crude and age/sex standardized all-cause mortality rates were determined for individuals with and without GCA between 2000 and 2018. Standardized mortality ratios (SMRs) were calculated to measure relative excess mortality over time. Differences in mortality between sexes and ages were also evaluated.

Results:

Population denominators among individuals 50 years and older with GCA and the General Population increased over time with 12,792 GCA patients and 5,456,966 comparators by 2018. Annual standardized mortality rates among the comparators steadily declined over time and were significantly lower than GCA morality rates (Figure). Annual GCA mortality rates fluctuated between 42-61 deaths per 1000 population (with overlapping confidence intervals) during the same time period. SMRs for GCA ranged from 1.28 (95% CI 1.08,1.47) at the lowest in 2002 to 1.96 (95% CI 1.84, 2.07) at the highest in 2018. GCA mortality rates and SMRs were highest among males and younger age groups.

Conclusion:

Over a 19-year period, mortality has remained increased among GCA patients relative to the general population. GCA mortality rates were higher among males and more premature deaths were occurring at younger age groups. In our study, improvements to the relative excess mortality for GCA patients over time (mortality gap) did not occur. Understanding cause-specific mortality and other factors are necessary to inform contributors to premature mortality among GCA patients.

References:

[1]Hill CL, et al. Risk of mortality in patients with giant cell arteritis: a systematic review and meta-analysis. Semin Arthritis Rheum. 2017;46(4):513-9.

Figure.

Acknowledgments: :

This study was supported by a CIORA grant

Disclosure of Interests:

Lillian Barra: None declared, Janet Pope Grant/research support from: AbbVie, Bristol-Myers Squibb, Eli Lilly & Company, Merck, Roche, Seattle Genetics, UCB, Consultant of: AbbVie, Actelion, Amgen, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Eicos Sciences, Eli Lilly & Company, Emerald, Gilead Sciences, Inc., Janssen, Merck, Novartis, Pfizer, Roche, Sandoz, Sanofi, UCB, Speakers bureau: UCB, Priscila Pequeno: None declared, Jodi Gatley: None declared, Jessica Widdifield: None declared

Development of a Concept Dictionary to Standardize Definitions and Classifications While Working With a Common Repository of Linked Administrative Data

IntroductionSupporting standardized approaches to common tasks is an important component of quality research using linked administrative data. Standard concept definitions and classifications are vital for ensuring accuracy and consistency in definitions between projects, and improving efficiency and quality. Other leading organizations have published online standard definitions of concepts and classifications. Objectives and ApproachWe developed a comprehensive concept dictionary using a standardized definition template of key components including data sources, codes, scale or range of values, validation details, limitations, SAS code and formats, related concepts, and MeSH terms. A web-based application (built on the Microsoft SharePoint platform) was developed to offer the latest web content authoring capabilities, and advanced search mechanisms enabling the user to search concepts by MeSH terms and key words. It also allowed for navigating concepts through category navigation including clickable categories and sub-categories. Entries will be reviewed annually to ensure the content remains up-to-date. ResultsTo date, ten concepts, with accompanying codes, have been published on the concept dictionary with another ten currently undergoing editorial review. These concepts span a variety of topics such as injuries, mental health and addictions-related outpatient services, and annual physical exams. New concepts written by content experts and reviewed by an editorial committee will be added on an on-going basis; thirty concepts are currently under development. Conclusion/ImplicationsDevelopment of a concept dictionary provides standardized definitions, algorithms and codes to ensure consistency and quality of research and analysis across multiple projects. Future aims include expansion of the internal organizational site to an external site through collaboration with key stakeholders.

Comparative hazards of acute myocardial infarction among hospitalized patients with methamphetamine- or cocaine-use disorders: A retrospective cohort study

BACKGROUND

It is assumed that recreational use of methamphetamine can trigger acute myocardial infarction (AMI) events, but estimates of longitudinal hazards of AMI among methamphetamine users are lacking.

METHODS

Retrospective cohort study: Competing-risks analysis was used to estimate time-to-AMI patterns in methamphetamine versus matched appendicitis (population-proxy) and matched cocaine (drug-control) groups. Cohorts were propensity-score-matched using demographic and clinical variables.

SETTING

California, 1990-2005.

PARTICIPANTS

Cohorts of individuals with no prior or concurrent history of AMI hospitalized with methamphetamine- (n = 73,056), cocaine- (n = 47,726), or appendicitis-related conditions (n = 330,109).

MEASUREMENTS

ICD-9/ICD-10 indications of AMI (ICD-9 410.X; ICD-10 I21.X) in death records or inpatient hospital data.

RESULTS

Patients in methamphetamine cohort were more likely to develop subsequent AMI in comparison to those in matched appendicitis cohort [Hazard ratio (HR): 1.41; 95% CI, 1.23-1.62, p < 0.0001], with increased risk most marked in young methamphetamine users (age 15-34 years; HR: 2.04; 95% CI, 1.63-2.57, p = 0. 0001). Risk was slightly increased vs. that in matched cocaine group (HR: 1.19; 95% CI, 1.02-1.39, p = 0. 029). Individuals in cocaine cohort were also more likely to experience AMI outcome vs. appendicitis cohort (HR: 1.25; 95% CI, 1.08-1.45, p = 0. 0023).

CONCLUSION

Our longitudinal data support results of earlier epidemiological studies suggesting that persons with methamphetamine- (or cocaine-) use disorders might have increased AMI risk. However, because of potential study limitations and the unexpectedly modest magnitude of the observed increased AMI hazard, these findings must be considered preliminary and require replication.

Impacts of Canada's minimum age for tobacco sales (MATS) laws on youth smoking behaviour, 2000-2014

BACKGROUND

Recently, the US Institute of Medicine has proposed that raising the minimum age for tobacco purchasing/sales to 21 years would likely lead to reductions in smoking behavior among young people. Surprisingly few studies, however, have assessed the potential impacts of minimum-age tobacco restrictions on youth smoking.

OBJECTIVE

To estimate the impacts of Canadian minimum age for tobacco sales (MATS) laws on youth smoking behaviour.

DESIGN

A regression-discontinuity design, using seven merged cycles of the Canadian Community Health Survey, 2000-2014.

PARTICIPANTS

Survey respondents aged 14-22 years (n=98 320).

EXPOSURE

Current Canadian MATS laws are 18 years in Alberta, Saskatchewan, Manitoba, Quebec, the Yukon and Northwest Territories, and 19 years of age in the rest of the country.

MAIN OUTCOMES

Current, occasional and daily smoking status; smoking frequency and intensity; and average monthly cigarette consumption.

RESULTS

In comparison to age groups slightly younger than the MATS, those just older had significant and abrupt increases immediately after the MATS in the prevalence of current smokers (absolute increase: 2.71%; 95% CI 0.70% to 4.80%; P=0.009) and daily smokers (absolute increase: 2.43%; 95% CI 0.74% to 4.12%; P=0.005). Average past-month cigarette consumption within age groups increased immediately following the MATS by 18% (95% CI 3% to 39%; P=0.02). There was no evidence of significant increases in smoking intensity for daily or occasional smokers after release from MATS restrictions.

CONCLUSION

The study provides relevant evidence supporting the effectiveness of Canadian MATS laws for limiting smoking among tobacco-restricted youth.

Assessing the impacts of Saskatchewan's minimum alcohol pricing regulations on alcohol-related crime

INTRODUCTION

Saskatchewan's introduction in April 2010 of minimum prices graded by alcohol strength led to an average minimum price increase of 9.1% per Canadian standard drink (=13.45 g ethanol). This increase was shown to be associated with reduced consumption and switching to lower alcohol content beverages. Police also informally reported marked reductions in night-time alcohol-related crime.

OBJECTIVES

This study aims to assess the impacts of changes to Saskatchewan's minimum alcohol-pricing regulations between 2008 and 2012 on selected crime events often related to alcohol use.

METHODS

Data were obtained from Canada's Uniform Crime Reporting Survey. Auto-regressive integrated moving average time series models were used to test immediate and lagged associations between minimum price increases and rates of night-time and police identified alcohol-related crimes. Controls were included for simultaneous crime rates in the neighbouring province of Alberta, economic variables, linear trend, seasonality and autoregressive and/or moving-average effects.

RESULTS

The introduction of increased minimum-alcohol prices was associated with an abrupt decrease in night-time alcohol-related traffic offences for men (-8.0%, P < 0.001), but not women. No significant immediate changes were observed for non-alcohol-related driving offences, disorderly conduct or violence. Significant monthly lagged effects were observed for violent offences (-19.7% at month 4 to -18.2% at month 6), which broadly corresponded to lagged effects in on-premise alcohol sales.

DISCUSSION

Increased minimum alcohol prices may contribute to reductions in alcohol-related traffic-related and violent crimes perpetrated by men. Observed lagged effects for violent incidents may be due to a delay in bars passing on increased prices to their customers, perhaps because of inventory stockpiling. [Stockwell T, Zhao J, Sherk A, Callaghan RC, Macdonald S, Gatley J. Assessing the impacts of Saskatchewan's minimum alcohol pricing regulations on alcohol-related crime. Drug Alcohol Rev 2017;36:492-501].

Low level of brain dopamine D2 receptors in methamphetamine abusers: association with metabolism in the orbitofrontal cortex

OBJECTIVE

The role of dopamine in the addictive process (loss of control and compulsive drug intake) is poorly understood. A consistent finding in drug-addicted subjects is a lower level of dopamine D2 receptors. In cocaine abusers, low levels of D2 receptors are associated with a lower level of metabolism in the orbitofrontal cortex. Because the orbitofrontal cortex is associated with compulsive behaviors, its disruption may contribute to compulsive drug intake in addicted subjects. This study explored whether a similar association occurs in methamphetamine abusers.

METHOD

Fifteen methamphetamine abusers and 20 non-drug-abusing comparison subjects were studied with positron emission tomography (PET) and [11C]raclopride to assess the availability of dopamine D2 receptors and with [18F]fluorodeoxyglucose to assess regional brain glucose metabolism, a marker of brain function.

RESULTS

Methamphetamine abusers had a significantly lower level of D2 receptor availability than comparison subjects (a difference of 16% in the caudate and 10% in the putamen). D2 receptor availability was associated with metabolic rate in the orbitofrontal cortex in abusers and in comparison subjects.

CONCLUSIONS

Lower levels of dopamine D2 receptor availability have been previously reported in cocaine abusers, alcoholics, and heroine abusers. This study extends this finding to methamphetamine abusers. The association between level of dopamine D2 receptors and metabolism in the orbitofrontal cortex in methamphetamine abusers, which replicates previous findings in cocaine abusers, suggests that D2 receptor-mediated dysregulation of the orbitofrontal cortex could underlie a common mechanism for loss of control and compulsive drug intake in drug-addicted subjects.

L-tryptophan attenuation of the dopaminergic and behavioral responses to cocaine

This study assessed the effects of acute intravenous L-tryptophan (neutral amino acid precursor for serotonin) administration on cocaine-induced dopaminergic responses. Male Sprague-Dawley rats were surgically implanted with guide cannulas in the nucleus accumbens 5 days prior to the study and with vascular catheters (carotid artery and jugular vein) on the day prior to the study. Using microdialysis, extracellular nucleus accumbens dopamine levels were measured in freely moving rats. Following a 2 h equilibration period, animals were randomized (n=7-8 per group) to receive either a constant intravenous (IV) infusion of L-tryptophan (200 mg/kg/h) or an equal volume (2 ml/h) of saline. Ninety minutes into the infusion, cocaine (20 mg/kg) was injected intra-peritoneally. Cocaine increased nucleus accumbens microdialysate dopamine levels (500% at 30 min). This was associated with marked hyperactivity. Tryptophan infusion elevated plasma tryptophan (8-fold), and blunted the cocaine-induced increase in nucleus accumbens microdialysate dopamine levels by approximately 60%. Furthermore, tryptophan attenuated the cocaine-induced locomotor activity. These neurochemical and behavioral effects of tryptophan were associated with a marked increase in brain tissue serotonin content. The results of these studies demonstrate the feasibility of acute dietary manipulation of neurochemical and behavioral responses to cocaine. The duration, adaptation and tolerance to these effects remain to be elucidated.

Differences in regional brain metabolic responses between single and repeated doses of methylphenidate

Studies investigating the acute effects of drugs of abuse on human brain metabolism have measured single doses whereas these drugs are mostly taken repeatedly. Here we compared the brain metabolic response to intravenous methylphenidate when given after a single dose to that when given after two sequential doses. Methylphenidate-induced changes in metabolism differed; whereas single doses tended to decrease metabolism, repeated doses tended to increase it, and these differences were significant in frontal, parietal and occipital cortices and hippocampus. This indicates that methylphenidate's metabolic effects vary with acute previous exposure and highlights the importance of studying drugs after single and repeated administration.

Parallel loss of presynaptic and postsynaptic dopamine markers in normal aging

Aging of the human brain is associated with a decline in dopamine (DA) function, generally interpreted as reflecting DA cell loss. Positron emission tomography studies revealed that in healthy individuals, the age-related losses in DA transporters (presynaptic marker) were associated with losses in D2 receptors (postsynaptic marker) rather than with increases as is known to occur with DA cell loss. This association was specific for DA synaptic markers, because they were not correlated with striatal metabolism. Furthermore, the association was independent of age, suggesting that a common mechanism regulates the expression of receptors and transporters irrespective of age.

Mapping the genes for haloperidol-induced catalepsy

The strain means for haloperidol-induced catalepsy were determined in the 26 strain BXD recombinant inbred series. The ED50 values ranged from 0.55 mg/kg (strain 30) to 7.9 mg/kg (strain 2). Heritability for the catalepsy response was 0.78 and the number of effective loci was estimated to be four. The strain means were correlated with the strain distribution patterns for 1300 marker loci of known chromosomal location and polymorphic between the C57Bl/6J and DBA/2J strains. Six quantitative trait loci (QTLs) were identified at P < .01. Two of the six QTLs were confirmed in a sample of B6XD2 F2 animals (n = 144), phenotyped for haloperidol response and genotyped for microsatellites closely linked to the QTLs. The confirmed QTL on chromosome 4 is near the b locus. The confirmed QTL on chromosome 9 is closely linked to Drd2, the D2 dopamine receptor gene. One hundred of the F2 individuals were phenotyped for D2 dopamine receptor binding using the ligand [125I] epidepride as the ligand. Consistent with previous results, the nonresponsive F2 individuals showed modestly higher receptor binding in all brain regions examined: the nucleus accumbens core, the nucleus accumbens shell, the lateral caudate putamen, the dorsomedial caudate putamen, the substantia nigra zona compacta and the ventral tegmental area. The DBA/2J allele of the chromosome 9 QTL was associated with higher receptor binding in all brain areas except the ventral tegmental area. Overall, the data illustrate that either near or part of Drd2 is a QTL which has significant effects on both haloperidol response and D2 dopamine receptor binding. However, the data also illustrate that most of the genetic variance in either haloperidol response or D2 dopamine receptor binding is not associated with Drd2.