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.
In the early days of CHÉOS, the Centre had a series known as “The Evidence Speaks,” a monograph series to keep media and the research community up-to-date with CHÉOS’ current research results in the health outcomes field.

Khakban A, Mohammadi T, Lynd LD, Mabbott DJ, Bouffet E, Gastonguay L, Zafari Z, Malkin D, Taylor MD, Marra CA. How do parents and providers trade-off between disability and survival? Preferences in treatment of pediatric medulloblastoma. Patient Pref Adherence. 2018 Oct 10;12:2103-10.

Dr. Larry Lynd, CHÉOS Health Economist Tima Mohammadi, and an international team of researchers collaborated to develop and test a best-worst scaling (BWS) tool to determine the treatment preferences in parents of children with medulloblastoma and their physicians. Specifically, the study looked at how preferences related to trade-offs between survival and disability. Medulloblastoma is a type of brain tumor that affects children. It can be treated, however its therapies, particularly radiation, can lead to neurodevelopmental problems. Molecular testing can guide the use of radiation to reduce unnecessary exposure and thereby reduce potentially adverse outcomes. However, the uncertainty in molecular testing results in a trade-off between test accuracy, survival, mental development, and other disability. A BWS, choice-based method was used where study participants were presented with 12 choice profiles consisting of variations on attributes like survival risk or level of disability and asked to indicate the best and worst features. The BWS was stratified by 10-year survival prognosis. Severity of adverse treatment effects used the Bloom’s scale for levels of disability; these ranged from ‘no disability’ to ‘severe disability’ which entails incapacity for self-care, need for schooling for intellectually impaired, and inability to walk or eat without help. Fifty-four parents participated and 176 providers from Toronto and Vancouver. The majority of parents were female (79%) while the majority of providers were male (64%). The parent’s children were affected with several types of brain tumors and were on average 10 years old at the time of the survey. Preferences differed based on the prognosis, but in general, parents valued survival over disability, while physicians had the opposite preference. Providers were more willing to risk recurrence in a child with a good prognosis and were more willing to take a survival risk to avoid severe disability. This study identified differences in the apparent values of the main stakeholders involved with decision making in paediatric medulloblastoma therapy and can help guide treatment options for children with different medulloblastoma prognosis.

Eide LS, Ranhoff AH, Lauck S, Fridlund B, Haaverstad R, Hufthammer KO, Kuiper KKJ, Nordrehaug JE, Norekvål TM; CARDELIR Investigators. Indwelling urinary catheters, aortic valve treatment and delirium: A prospective cohort study. BMJ Open. 2018 Nov 1;8(11):e021708.

CHÉOS Scientist Dr. Sandra Lauck joined a group of Norwegian researchers to conduct a secondary analysis of data from the Delirium in Octogenarians Undergoing Cardiac Surgery or Intervention (CARDELIR) study, a prospective cohort of patients undergoing elective SAVR or TAVI for aortic stenosis. Surgical aortic valve replacement (SAVR) is a cardiac procedure that requires general anaesthesia and cardiopulmonary bypass. Transcatheter aortic valve implantation (TAVI) is an alternative procedure that is minimally invasive and the treatment option of choice for high-risk patients. Due to the complexities of open-heart surgery in SAVR, an indwelling urinary catheter (IUC) is used to monitor blood and renal events during and after the procedure. An IUC is also commonly used during the TAVI procedure despite growing questions about their necessity during the shorter and less-invasive TAVI. In older patients (>80), delirium following these surgeries may be linked to the use of IUCs and has been showed to be associated with poor health outcomes in this population. Of the 136 patients analyzed, 63 of them were treated with TAVI; they were also older and had more comorbidities than those who were treated with SAVR. Patients who developed delirium used an IUC for 63 hours on average, compared to 43 hours in patients without delirium. A greater proportion (66 vs. 44%) of SAVR patients developed delirium compared to SAVR. Development of delirium was associated with longer IUC use however logistical regression revealed that the association between length of IUC use and delirium was stronger for TAVI compared to SAVR patients. Specifically, each hour of IUC use in TAVI was associated with an estimated 4% increase in odds of delirium compared to an increase in odds of only 1% in SAVR. This association had not previously been shown and calls for more research to evaluate whether or not IUC use can be reduced or eliminated in stable TAVI patients and for research into the use of biomarkers prior to surgery to measure risk factors for delirium.

Kalyan S, Goshtesabi A, Sarray S, Joannou A, Almawi WY. Assessing C reactive protein/albumin ratio as a new biomarker for polycystic ovary syndrome: A case-control study of women from Bahraini medical clinics. BMJ Open. 2018 Oct 27;8(10):e021860.

Polycystic ovary syndrome (PCOS) is the most common reproductive disorder, occurring in 5–15% of premenopausal women, and is becoming increasingly common. PCOS is associated with increased risk of a number of health issues, including cardiovascular disease and diabetes, however, its cause is unknown. The central contributor to these heightened risks is thought to be chronic inflammation, suggested by significantly higher systemic levels of C reactive protein (CRP). Another blood marker, albumin, is decreased in people experiencing chronic inflammation and the ratio of CRP to albumin has been shown to be elevated in women with PCOS compared to controls. Building off of this previous research, CHÉOS’ Dr. Shirin Kalyan and other researchers in UBC’s Division of Endocrinology investigated the association between the CRP/albumin ratio and PCOS in a group of premenopausal women in Bahrain. Two-hundred women with PCOS and 199 healthy controls were recruited and provided blood samples that were tested for hormone and relevant biomarker levels. The analysis showed for the first time that albumin, which was not previously thought to be a marker for interest in PCOS, was significantly reduced in women with PCOS compared to controls. The researchers also showed that the CRP/albumin ratio was correlated more strongly with PCOS than traditional measures (free androgens and insulin resistance) and was better than CRP alone in predicting PCOS. This study was able to overcome the shortcomings of previous research by accounting for many relevant confounding variables and by using the more sensitive CRP/albumin ratio. However, the study design (case-control design) limits the ability of the researchers to assess the predictive ability of the ratio and requires follow up with a prospective study to determine the utility of CRP/albumin in predicting the development of diseases related to chronic inflammation and PCOS.