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The Evidence Speaks

The Evidence Speaks (October 2019)

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The Evidence Speaks Series is a recurring feature highlighting the latest in CHÉOS research. This series features summaries of select publications as well as in-depth features on the latest work from our investigators. The Series is designed to keep media and the research community up-to-date with CHÉOS’ current research results in the health outcomes field.

Fergusson NA, Ahkioon S, Nagarajan M, Park E, Ding Y, Ayas N, Dhingra VK, Chittock DR, Griesdale DEG. Association of intensive care unit occupancy during admission and inpatient mortality: a retrospective cohort study. Can J Anaesth. 2019 Sep 16 epub ahead of print.

A study co-authored by CHÉOS Scientist Dr. Najib Ayas has demonstrated the negative effects of intensive care unit (ICU) capacity strain on patient survival. Capacity strain is the difference between available resources, like beds and staff, and the demand on those resources. Capacity strain is one of the organizational factors that can determine outcomes for critically ill patients. Because strain can be measured using multiple approaches, there is conflicting evidence about its impact on patients, and day-by-day trends in ICU outcomes can be missed. In response, Dr. Ayas and researchers from UBC and Vancouver Coastal Health conducted a retrospective analysis of ICU admissions to Vancouver General Hospital over a 7-year period. Using individual admission-level data, the researchers defined ICU strain as the number of bed hours used in a day divided by the total number of bed hours available for that day and examined its effect on patient mortality. Specifically, the team looked at death that occurred in the ICU or in the hospital after ICU discharge as well as on early mortality (death in the ICU within 72 hours of admission). They found that patients who were admitted during days of excessive strain (over 100% occupancy) were more likely to die in hospital than patients who were admitted during less-strained days. The researchers found no effect of ICU strain on early mortality, which could suggest that mortality within 72 hours is affected more by patient factors than by strain. Other strain-related factors, like afterhours admission, weekend admission, or season were not related to either mortality outcome. Overall, these results highlight the negative clinical consequences of ICU occupancy and capacity strain for patients.

Gilbert M, Salway T, Haag D, Elliot E, Fairley C, Krajden M, Grennan T, Shoveller J, Ogilvie G. A cohort study comparing rate of repeat testing for sexually transmitted and blood-borne infections between clients of an internet-based testing programme and of sexually transmitted infection clinics in Vancouver, Canada. Sex Transm Infect. 2019 Nov;95(7):540-6.

A new study published by researchers at the BC Centre for Disease Control (BCCDC), including CHÉOS Scientist Dr. Troy Grennan, highlights the potential effectiveness of internet-based testing for sexually transmitted and blood-borne infections (STBBIs). Increased access to STBBI testing improves patient and population outcomes by optimizing the timeliness of diagnoses and reducing the risk of secondary transmissions. The BCCDC developed an internet-based STBBI testing service called GetCheckedOnline (GCO), a program that allows clients to complete an online risk assessment, create lab forms, submit their samples anonymously, and get their results electronically. Previous research from this group has shown that GCO is acceptable and convenient to clients, that it adequately protects privacy, and that it is used by people who face barriers to clinical testing. But a single STBBI test is not enough; repeat testing is needed to maintain the benefit of such a screening program. Accordingly, the BCCDC researchers designed a study to test whether the online service improved the frequency that clients were getting tested and how it overlapped with their use of traditional clinic-based screening methods. All GCO clients who had received at least one test within the first 29 months of the program’s launch were included (1,093 people), along with those who received testing at three BCCDC sexual health clinics during the same time period (18,404 people). They found that, compared to those who used traditional testing services, GCO clients were more likely to be white, to be women, and to have had a previous STBBI diagnoses. Among people who received more than one test (10,863 people), the rate of repeat testing was over 20 per cent higher in GCO compared to clinic clients. Twenty-five per cent of GCO clients who received multiple tests used both online and traditional testing services. This research suggests that GCO facilitates higher rates of STBBI testing and that it is complimentary to existing clinic-based services.

Waclawik K, Jones AA, Barbic SP, Gicas KM, O’Connor TA, Smith GN, Leonova O, Mathias S, Barr AM, Procyshyn RM, Lang DJ, Woodward ML, MacEwan WG, Panenka WJ, Yamamoto A, Honer WG, Thornton AE. Cognitive Impairment in Marginally Housed Youth: Prevalence and Risk Factors. Frontiers Public Heal. 2019 Oct;7:270.

CHÉOS Scientists Drs. Skye Barbic and Steve Mathias are co-authors on one of the first studies on the cognitive functioning and associated risk factors of marginally housed youth. Homeless and marginally housed youth have increased rates of psychiatric illness, substance use, and other health issues that impair cognitive function. In turn, cognitive impairment can be a major barrier to quality of life and health and prevent or limit access and retention in treatment and housing. There has been very little research about the risk factors associated with cognitive functioning in homeless and vulnerably housed youth, even though they are among the most vulnerable populations in our society. A collaboration of researchers from UBC and SFU, including Drs. Barbic and Mathias, enrolled people under the age of 30 already participating The Hotel Study, an ongoing, 10-year longitudinal investigation of public health in Vancouver’s Downtown Eastside. Study participants were assessed by a psychiatrist for any applicable diagnoses and underwent psychological assessment covering the four areas of cognition: verbal memory, sustained attention, processing speed, and cognitive flexibility, a measure of the one’s ability to switch from thinking about one concept to another. From these assessments, a measure of cognitive impairment for each domain was produced. Participants had high rates of mental illness and substance dependence, including schizophrenia, mood disorder, opioid dependence, and stimulant dependence. Nearly three-quarters of participants had not finished high school but their mean estimated IQ was in the average range. Over forty per cent of participants showed mild cognitive impairment and sixteen per cent were severely impaired across multiple domains. Memory and sustained attention domains were the most commonly impaired domains. The analysis showed several developmental and historical risk factors for cognitive impairment, including indicators of abnormal neurological development, younger age at the first instance of homelessness, and longer duration of homelessness. Besides stimulant dependence and hepatitis C, most health risk factors did not predict cognitive impairment. These results demonstrate the high prevalence of cognitive difficulties in this population, the need to prioritize treatment of modifiable factors like hepatitis C and stimulant dependence, and the importance of early intervention to improve long-term outcomes.