Irfan A Dhalla

St. Michael's Hospital, Toronto, Ontario, Canada

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Publications (76)543.89 Total impact

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    ABSTRACT: The use of opioids for noncancer pain is widespread, and more than 16,000 die of opioid-related causes in the United States annually. The patients at greatest risk of death are those receiving high doses of opioids. Whether sex influences the risk of dose escalation or opioid-related mortality is unknown. We conducted a cohort study using healthcare records of 32,499 individuals aged 15 to 64 who commenced chronic opioid therapy for noncancer pain between April 1, 1997 and December 31, 2010 in Ontario, Canada. Patients were followed from their first opioid prescription until discontinuation of therapy, death from any cause or the end of the study period. Among patients receiving chronic opioid therapy, 589 (1.8%) escalated to high dose therapy and n = 59 (0.2%) died of opioid-related causes while on treatment. After multivariable adjustment, men were more likely than women to escalate to high-dose opioid therapy (adjusted hazard ratio 1.44; 95% confidence interval 1.21 to 1.70) and twice as likely to die of opioid-related causes (adjusted hazard ratio 2.04; 95% confidence interval 1.18 to 3.53). These associations were maintained in a secondary analysis of 285,520 individuals receiving any opioid regardless of the duration of therapy. Men are at higher risk than women for escalation to high-dose opioid therapy and death from opioid-related causes. Both outcomes were more common than anticipated.
    PLoS ONE 08/2015; 10(8):e0134550. DOI:10.1371/journal.pone.0134550 · 3.23 Impact Factor
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    ABSTRACT: The objectives of our study were to assess trends in afterhours medical imaging utilization for emergency department (ED) and inpatient (IP) patient populations from 2006-2013, including analysis by modality and specialty and with adjustment for patient volume. For this retrospective study, we reviewed the number of CT, MRI, and ultrasound studies performed for the ED and IP patients during the afterhours time period (5pm - 8am on weekdays and 24 hours on weekends and statutory holidays) from 2006-2013 at three different Canadian academic hospitals. We used the Jonckheere-Terpstra (JT) test to determine statistical significance of imaging and patient volume trends. A regression model was used to examine whether there was an increasing trend over time in the volume of imaging tests per 1000 patients. For all three sites from 2006-2013 during the afterhours time period: There was a statistically significant increasing trend in total medical imaging volume, which also held true when the volumes were assessed by modality and by specialty. There was a statistically significant increasing trend in ED and IP patient volume. When medical imaging volumes were adjusted for patient volumes, there was a statistically significant increasing trend in imaging being performed per patient. Afterhours medical imaging volumes demonstrated a statistically significant increasing trend at all three sites from 2006-2013 when assessed by total volume, modality, and specialty. During the same time period and at all three sites, the ED and IP patient volumes also demonstrated a statistically significant increasing trend with more medical imaging, however, being performed per patient. Copyright © 2015 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.
    Canadian Association of Radiologists Journal 07/2015; DOI:10.1016/j.carj.2015.03.002 · 0.52 Impact Factor
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    ABSTRACT: Accurate and complete documentation of hospitalized patients' code status is important to ensure that healthcare providers take appropriate action in the event of a cardiac arrest. Determine the frequency and clinical relevance of incomplete and inconsistent code status documentation. Point-prevalence study. Academic medical centers. Patients admitted to general internal medicine wards. Frequency and clinical relevance of inconsistent code status documentation across 5 documentation sources. Thirty-eight (20%; 95% confidence interval [CI], 14%-26%) of 187 patients had complete and consistent code status documentation. Another 27 (14%; 95% CI, 9%-19%) patients had no code status documentation. The remaining 122 (65%; 95% CI, 58%-72%) patients had at least 1 code status documentation inconsistency. Of these, 38 (20%; 95% CI, 14%-26%) patients had a clinically relevant code status documentation inconsistency. Multivariate logistic regression analysis demonstrated that increased age (odds ratio [OR] = 1.07 [95% CI, 1.05-1.10] for every 1-year increase in age, P < 0.001) and patients receiving comfort measures (OR = 9.39 [95% CI, 1.35-65.19], P = 0.02) were independently associated with a clinically relevant code status documentation inconsistency. Incomplete and inconsistent documentation of code status occurred frequently in hospitalized patients, especially elderly patients and patients receiving comfort measures. Having multiple, poorly integrated code status documentation sources leads to a significant number of concerning inconsistencies that create opportunities for healthcare providers to inappropriately deliver or withhold resuscitative measures that conflict with patients' expressed wishes. Institutions need to be aware of this potential documentation hazard and take steps to minimize code status documentation inconsistencies. Journal of Hospital Medicine 2015. © 2015 Society of Hospital Medicine. © 2015 Society of Hospital Medicine.
    Journal of Hospital Medicine 04/2015; 10(8). DOI:10.1002/jhm.2348 · 2.30 Impact Factor
  • Reena Pattani · Peter E Wu · Irfan A Dhalla
    Canadian Medical Association Journal 02/2015; 187(3):207. DOI:10.1503/cmaj.115-0007 · 5.96 Impact Factor
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    ABSTRACT: The incidence of neonatal opioid withdrawal is increasing in both Canada and the United States. However, the degree to which the treatment of pain with opioids, rather than the misuse of prescription opioids or heroin, contributes to the prevalence of neonatal opioid withdrawal remains unknown. We conducted a retrospective, population-based, cross-sectional study between 1992 and 2011 in Ontario with 2 objectives. First, we determined the annual incidence of neonatal abstinence syndrome. Second, using data from a subset of women eligible for publicly funded prescription drugs, we determined what proportion of women who deliver an infant with neonatal abstinence syndrome were given a prescription for an opioid before and during pregnancy. The incidence of neonatal abstinence syndrome in Ontario increased 15-fold during the study period, from 0.28 per 1000 live births in 1992 to 4.29 per 1000 live births in 2011. During the final 5 years of the study, we identified 927 deliveries of infants with neonatal abstinence syndrome to mothers who were public drug plan beneficiaries. Of these mothers, 67% had received an opioid prescription in the 100 days preceding delivery, including 53.3% who received methadone, an increase from 28.6% in the interval spanning 1 to 2 years before delivery (p < 0.001). Prescription for nonmethadone opioids decreased from 38% to 17% (p < 0.001). The incidence of neonatal opioid withdrawal in Ontario has increased substantially over the last 20 years. Most of the women in this cohort who delivered an infant with neonatal abstinence syndrome had received a prescription for an opioid both before and during their pregnancy.
    01/2015; 3(1):E55-61. DOI:10.9778/cmajo.20140065
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    ABSTRACT: The Toronto Central Community Care Access Centre is leading a collaborative local health integration network systemic change initiative to implement and evaluate a practical model of integrated care for older adults with complex needs. The approach is embedded in the community where older adults and their families live and is designed to first and foremost improve the quality of care while ultimately bending the cost curve. The model is leveraging and aligning existing system resources by bringing together sectors from across the health system to create ways of working that build capacity in the system to be more responsive to this population. Outcomes to date will be discussed and next steps described. The secondary goal was to understand the key elements of this integration that can be scaled locally and across the province. Copyright © 2014 Longwoods Publishing.
    Healthcare quarterly (Toronto, Ont.) 10/2014; 17(3):61-9. DOI:10.12927/hcq.2014.24022
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    ABSTRACT: Background Activity-based funding (ABF) of hospitals is a policy intervention intended to re-shape incentives across health systems through the use of diagnosis-related groups. Many countries are adopting or actively promoting ABF. We assessed the effect of ABF on key measures potentially affecting patients and health care systems: mortality (acute and post-acute care); readmission rates; discharge rate to post-acute care following hospitalization; severity of illness; volume of care. Methods We undertook a systematic review and meta-analysis of the worldwide evidence produced since 1980. We included all studies reporting original quantitative data comparing the impact of ABF versus alternative funding systems in acute care settings, regardless of language. We searched 9 electronic databases (OVID MEDLINE, EMBASE, OVID Healthstar, CINAHL, Cochrane CENTRAL, Health Technology Assessment, NHS Economic Evaluation Database, Cochrane Database of Systematic Reviews, and Business Source), hand-searched reference lists, and consulted with experts. Paired reviewers independently screened for eligibility, abstracted data, and assessed study credibility according to a pre-defined scoring system, resolving conflicts by discussion or adjudication. Results Of 16,565 unique citations, 50 US studies and 15 studies from 9 other countries proved eligible (i.e. Australia, Austria, England, Germany, Israel, Italy, Scotland, Sweden, Switzerland). We found consistent and robust differences between ABF and no-ABF in discharge to post-acute care, showing a 24% increase with ABF (pooled relative risk = 1.24, 95% CI 1.18–1.31). Results also suggested a possible increase in readmission with ABF, and an apparent increase in severity of illness, perhaps reflecting differences in diagnostic coding. Although we found no consistent, systematic differences in mortality rates and volume of care, results varied widely across studies, some suggesting appreciable benefits from ABF, and others suggesting deleterious consequences. Conclusions Transitioning to ABF is associated with important policy- and clinically-relevant changes. Evidence suggests substantial increases in admissions to post-acute care following hospitalization, with implications for system capacity and equitable access to care. High variability in results of other outcomes leaves the impact in particular settings uncertain, and may not allow a jurisdiction to predict if ABF would be harmless. Decision-makers considering ABF should plan for likely increases in post-acute care admissions, and be aware of the large uncertainty around impacts on other critical outcomes.
    PLoS ONE 10/2014; 9:e109975. DOI:10.1371/journal.pone.0109975 · 3.23 Impact Factor
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    ABSTRACT: The increased use of opioid analgesics, sedative hypnotics and stimulants, coupled with the associated risks of overdose have raised concerns around the inappropriate prescribing of these monitored drugs. We assessed the impact of new legislation, the Narcotics Safety and Awareness Act, and a centralized Narcotics Monitoring System (implemented November 2011 and May 2012, respectively), on the dispensing of prescriptions suggestive of misuse. We conducted a time series analysis of publicly funded prescriptions for opioids, benzodiazepines and stimulants dispensed monthly in Ontario from January 2007 to May 2013, based on information in the Ontario Public Drug Benefit Database. In the primary analysis, a prescription was deemed potentially inappropriate if it was dispensed within 7 days of an earlier prescription and was for at least 30 tablets of a drug in the same class as the earlier prescription, but originated from a different physician and a different pharmacy. After enactment of the new legislation, the prevalence of potentially inappropriate opioid prescriptions decreased by 12.5% in 6 months (from 1.6% in October 2011 to 1.4% in April 2012; p = 0.01). No further significant change was observed after the introduction of the narcotic monitoring system (p = 0.8). By May 2013, the prevalence had dropped to 1.0%. Inappropriate benzodiazepine prescribing was significantly influenced by both the legislation (p < 0.001) and the monitoring system (p = 0.05), which together reduced potentially inappropriate prescribing by 50.0% between October 2011 and May 2013 (from 0.4% to 0.2%). The prevalence of potentially inappropriate prescribing of stimulants was significantly influenced by the introduction of the monitoring system in May 2012, falling from 0.7% in April 2012 to 0.3% in May 2013 (p = 0.02). For a select group of drugs prone to misuse and diversion, legislation and a prescription monitoring program reduced the prevalence of prescriptions suggestive of misuse. This suggests that regulatory interventions can promote appropriate prescribing which could potentially be applied to other jurisdictions and drugs of concern.
    10/2014; 2(4):E256-E261. DOI:10.9778/cmajo.20140027
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    ABSTRACT: Importance Hospital readmissions are common and costly, and no single intervention or bundle of interventions has reliably reduced readmissions. Virtual wards, which use elements of hospital care in the community, have the potential to reduce readmissions, but have not yet been rigorously evaluated.Objective To determine whether a virtual ward—a model of care that uses some of the systems of a hospital ward to provide interprofessional care for community-dwelling patients—can reduce the risk of readmission in patients at high risk of readmission or death when being discharged from hospital.Design, Setting, and Patients High-risk adult hospital discharge patients in Toronto were randomly assigned to either the virtual ward or usual care. A total of 1923 patients were randomized during the course of the study: 960 to the usual care group and 963 to the virtual ward group. The first patient was enrolled on June 29, 2010, and follow-up was completed on June 2, 2014.Interventions Patients assigned to the virtual ward received care coordination plus direct care provision (via a combination of telephone, home visits, or clinic visits) from an interprofessional team for several weeks after hospital discharge. The interprofessional team met daily at a central site to design and implement individualized management plans. Patients assigned to usual care typically received a typed, structured discharge summary, prescription for new medications if indicated, counseling from the resident physician, arrangements for home care as needed, and recommendations, appointments, or both for follow-up care with physicians as indicated.Main Outcomes and Measures The primary outcome was a composite of hospital readmission or death within 30 days of discharge. Secondary outcomes included nursing home admission and emergency department visits, each of the components of the primary outcome at 30 days, as well as each of the outcomes (including the composite primary outcome) at 90 days, 6 months, and 1 year.Results There were no statistically significant between-group differences in the primary or secondary outcomes at 30 or 90 days, 6 months, or 1 year. The primary outcome occurred in 203 of 959 (21.2%) of the virtual ward patients and 235 of 956 (24.6%) of the usual care patients (absolute difference, 3.4%; 95% CI, −0.3% to 7.2%; P = .09). There were no statistically significant interactions to indicate that the virtual ward model of care was more or less effective in any of the prespecified subgroups.Conclusions and Relevance In a diverse group of high-risk patients being discharged from the hospital, we found no statistically significant effect of a virtual ward model of care on readmissions or death at either 30 days or 90 days, 6 months, or 1 year after hospital discharge.Trial Registration Identifier: NCT01108172
    JAMA The Journal of the American Medical Association 10/2014; 312(13):1305-1312. DOI:10.1001/jama.2014.11492 · 35.29 Impact Factor
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    Irfan A Dhalla · Sumit R Majumdar
    Journal of General Internal Medicine 09/2014; 29(11). DOI:10.1007/s11606-014-3023-6 · 3.45 Impact Factor
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    ABSTRACT: Objective: To describe trends in rates of prescribing of high-dose opioid formulations and variations in opioid product selection across Canada. Design: Population-based, cross-sectional study. Setting: Canada. Participants: Retail pharmacies dispensing opioids between January 1, 2006, and December 31, 2011. Main outcome measures: Opioid dispensing rates, reported as the number of units dispensed per 1000 population, stratified by province and opioid type. Results: The rate of dispensing high-dose opioid formulations increased 23.0%, from 781 units per 1000 population in 2006 to 961 units per 1000 population in 2011. Although these rates remained relatively stable in Alberta (6.3% increase) and British Columbia (8.4% increase), rates in Newfoundland and Labrador (84.7% increase) and Saskatchewan (54.0% increase) rose substantially. Ontario exhibited the highest annual rate of high-dose oxycodone and fentanyl dispensing (756 tablets and 112 patches per 1000 population, respectively), while Alberta's rate of high-dose morphine dispensing was the highest in Canada (347 units per 1000 population). Two of the highest rates of high-dose hydromorphone dispensing were found in Saskatchewan and Nova Scotia (258 and 369 units per 1000 population, respectively). Conversely, Quebec had the lowest rate of high-dose oxycodone and morphine dispensing (98 and 53 units per 1000 population, respectively). Conclusion: We found marked interprovincial variation in the dispensing of high-dose opioid formulations in Canada, emphasizing the need to understand the reasons for these differences, and to consider developing a national strategy to address opioid prescribing.
    Canadian family physician Medecin de famille canadien 09/2014; 60(9):826-32. · 1.34 Impact Factor
  • Sharan Lail · Kelly Sequeira · Jenny Lieu · Irfan A Dhalla
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    ABSTRACT: Harms associated with prescription opioids are a major and increasing public health concern. Prescribing of opioids for inpatients may contribute to the problem, especially if primary care practitioners continue opioid therapy that is initiated in hospital.
    The Canadian journal of hospital pharmacy 09/2014; 67(5):337-42. DOI:10.4212/cjhp.v67i5.1387
  • Michael Law · Jillian Kratzer · Irfan Dhalla
    Canadian Medical Association Journal 07/2014; 186(10):779. DOI:10.1503/cmaj.114-0054 · 5.96 Impact Factor
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    ABSTRACT: Background and AimsThe burden of premature mortality due to opioid-related death has not been fully characterized. We calculated temporal trends in the proportion of deaths attributable to opioids and estimated years of potential life lost (YLL) due to opioid-related mortality in Ontario, Canada.DesignCross-sectional study.SettingOntario, Canada.ParticipantsIndividuals who died of opioid-related causes between January 1991 and December 2010.MeasurementsWe used the Registered Persons Database and data abstracted from the Office of the Chief Coroner to measure annual rates of opioid-related mortality. The proportion of all deaths related to opioids was determined by age group in each of 1992, 2001 and 2010. The YLL due to opioid-related mortality were estimated, applying the life expectancy estimates for the Ontario population.FindingsWe reviewed 5935 opioid-related deaths in Ontario between 1991 and 2010. The overall rate of opioid-related mortality increased by 242% between 1991 (12.2 per 1 000 000 Ontarians) and 2010 (41.6 per 1 000 000 Ontarians; P < 0.0001). Similarly, the annual YLL due to premature opioid-related death increased threefold, from 7006 years (1.3 years per 1000 population) in 1992 to 21 927 years (3.3 years per 1000 population) in 2010. The proportion of deaths attributable to opioids increased significantly over time within each age group (P < 0.05). By 2010, nearly one of every eight deaths (12.1%) among individuals aged 25–34 years was opioid-related.Conclusions Rates of opioid-related deaths are increasing rapidly in Ontario, Canada, and are concentrated among the young, leading to a substantial burden of disease.
    Addiction 07/2014; 109(9). DOI:10.1111/add.12598 · 4.74 Impact Factor
  • Lianne Jeffs · Irfan Dhalla · Roberta Cardoso · Chaim M Bell
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    ABSTRACT: Abstract An understanding of what complex medical patients with chronic conditions, family members and healthcare professionals perceive to be the key reasons for the readmission is important to preventing their occurrence. In this context, we undertook a study to understand the perceptions of patients, family members and healthcare professionals regarding the reasons for, and preventability of, readmissions. An exploratory case design with semi-structured interviews was conducted with 49 participants, including patients, family members, nurses, case managers, physicians, discharge planners from a general internal medicine unit at a large and academic hospital. Data were analyzed using a directed content analysis approach that involved three investigators. Two contrasting themes emerged from the analysis of interview data set. The first theme was readmissions as preventable occurrences. Our analyses elucidated contributing factors to readmissions during the patients' hospital stay and after the patients were discharged. The second theme was readmissions as inevitable, occurring due to the progression of disease. Our study findings indicate that some readmissions are perceived to be inevitable due to the burden of disease while others are perceived to be preventable and associated with factors both in hospital and post-discharge. Continued interprofessional efforts are required to identify patients at risk for readmission and to organize and deliver care to improve health outcomes after hospitalization.
    Journal of Interprofessional Care 06/2014; 28(6):1-6. DOI:10.3109/13561820.2014.923988 · 1.40 Impact Factor
  • Reena Pattani · Peter E Wu · Irfan A Dhalla
    Canadian Medical Association Journal 05/2014; 186(10). DOI:10.1503/cmaj.131053 · 5.96 Impact Factor
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    ABSTRACT: Guidance regarding appropriate and cost-effective use of prescription drugs is published in the Ontario Drug Benefit Formulary in the form of "therapeutic notes." We conducted a cross-sectional study of all residents of Ontario aged 66 and older who received a new prescription for one of two drugs, aliskiren or sitagliptin, between December 1, 2008 and March 31, 2012 to determine how frequently such guidance is followed. Approximately half of initial prescriptions for aliskiren and sitagliptin were prescribed in a manner that did not conform to the therapeutic note recommendations (51.4% and 49.3%, respectively). Given this high rate of non-conformance, policy makers may wish to use other mechanisms to influence prescriber behaviour to improve the quality and efficiency of healthcare.
    05/2014; 9(4):20-30. DOI:10.12927/hcpol.2014.23812
  • Michael R Law · Jillian Kratzer · Irfan A Dhalla
    Canadian Medical Association Journal 03/2014; 186(12). DOI:10.1503/cmaj.130913 · 5.96 Impact Factor
  • Dahlia Y Balaban · Irfan A Dhalla · Michael R Law · Chaim M Bell
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    ABSTRACT: Generic drugs offer a less expensive and therapeutically equivalent alternative to brand name drugs. Nevertheless, many Canadian private drug plans continue to pay for brand name drugs even after generics become available. The objective of this study was to quantify the excess spending resulting from this practice. We used the IMS Brogan PharmaStat database to study private-plan drug spending in Ontario from 2000 to 2009. We focused on three widely used drug classes: proton pump inhibitors (PPIs), selective serotonin reuptake inhibitors (SSRIs), and angiotensin-converting enzyme (ACE) inhibitors. For each specific molecule, we determined the difference between what private plans spent on the brand name version and what would have been spent if an available generic version of the same molecule had been purchased instead. We found that prescriptions paid for by private drug plans were often filled with brand name drugs after generics became available. This led to excess private spending of more than Can$107.8 million for these three drug classes over our study period: Can$54.4 million for PPIs, Can$32.4 million for SSRIs and Can$21.0 million for ACE inhibitors. Brand name drugs continue to be reimbursed by Canadian private drug plans at higher prices even after less expensive generic alternatives are available. By mandating generic substitution, substantial cost savings on benefit plans could be achieved.
    Applied Health Economics and Health Policy 08/2013; 11(5). DOI:10.1007/s40258-013-0052-y

Publication Stats

1k Citations
543.89 Total Impact Points


  • 2012–2015
    • St. Michael's Hospital
      Toronto, Ontario, Canada
  • 2002–2015
    • University of Toronto
      • • Institute of Health Policy, Management and Evaluation
      • • Department of Medicine
      Toronto, Ontario, Canada
  • 2013
    • Women's College Hospital
      Toronto, Ontario, Canada
  • 2011
    • Christus St. Michaels' Hospital
      텍사캐나, Arkansas, United States