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  • 8/3/2019 Insite Response to Allegations

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    Urban Health Research InitiativeBC Centre for Excellence in HIV/[email protected]://uhri.cfenet.ubc.ca

    Critique of Lancet study of Vancouvers supervised injection site andoverdose: Authors response

    In 2011, our research team at the British Columbia Centrefor Excellence in HIV/AIDSUniversity of British Columbia(Vancouver, Canada) published a study in the medical journal Te Lancet (Marshall et al., Reduction in overdose mortality a ter the opening o North Americas frst medically supervised sa er injecting acility: A retrospective population-based study . Lancet , 2011; 377(9775): 1429-

    1437) that demonstrated a 35% reduction in overdose inproximity to Vancouvers supervised injection site followingthe programs opening. Te data presented in the study andthe methodological approach used were subjected to extensivescienti c peer review. Tis independent review processcon rmed the appropriateness of the data and the methodsthat we employed. Despite this extensive independent review process, REAL Women of Canada and the Drug PreventionNetwork of Canada (DPNC) recently commissioned a reportthat critiqued the study. Te report has not been subjected toscienti c peer review, nor has it been published in conventional

    academic format. However, this report was used as the basis of a complaint submitted by Mr. Gary Christian of Drug Free Australia to the University of British Columbia.

    As authors of the Lancet study, we prepared a response tothis report and to the complaint forwarded to the University of British Columbia. Te complaint was processed accordingto established university protocol and externally reviewed by a relevant expert. Te complaint was found to be without merit and not based on scientifc act and was dismissed.

    We also wish to point out that Mr. Christian and co-authorshave used similar strategies to call into question the scienti c

    evaluation of the Sydney (Australia) supervised injection site.Tese critiques have been reviewed by the relevant authoritiesand found to be baseless. Te Australia Medical Associationand the Royal Australasian College of Physicians both rejectedsimilar e orts by Mr. Christian and Drug Free Australia to

    dispute the science derived from the evaluation of the Sydnesupervised injection site.

    Here, we provide speci c responses to points raised by MChristian and co-authors.

    1. Trends in overdose deaths: Mr. Christian and colleagueallege that we manipulated data to show that overdose deathdeclined in the wake of the opening of Insite (Vancouversupervised injection site). Using BC Vital Statistics data, thargue that overdose deaths increased rather than decreasduring the period considered in our study. Tis apparentdiscrepancy is explained by several aws in their analysis. Four study in the Lancet focused on a de ned area of interein close proximity to Insite that included 41 city blocks, thcentroid of each being within 500 metres of the facility. Tisarea was selected on the basis of the high concentration single-room occupancy hotels in the area and data indicatinthat 70% of daily Insite users live within this area. Because whypothesized that Insite would have the biggest e ect whe

    most Insite users live, we compared changes in rates of faoverdose in this concentrated drug use area to changes in ratof overdose in the rest of the City of Vancouver (the controarea). However, the data considered in the REAL WomenDPNC report examined the entire Downtown Eastside LocaHealth Area (LHA)an area that is much larger and includeapproximately 400 city blocks. Te problem with this approachis demonstrated in Figure 3 of the Lancet study (next pagereproduced with permission), which shows that the largereduction in overdose deaths was observed in the concentratedrug use area in close proximity to Insite (i.e., within 4 blocks

    while the apparent e ect of the facility markedly diminishoutside this area.

    Crudely considering this much larger 400-block LocHealth Area masks the decline in overdoses we observed whiagain, was limited to the concentrated drug use area whe

    http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.publicaffairs.ubc.ca/2011/10/18/allegations-against-ubc-researchers%E2%80%99-study-on-insite-%E2%80%9Cwithout-merit%E2%80%9D-independent-reviewer/http://www.publicaffairs.ubc.ca/2011/10/18/allegations-against-ubc-researchers%E2%80%99-study-on-insite-%E2%80%9Cwithout-merit%E2%80%9D-independent-reviewer/http://www.publicaffairs.ubc.ca/2011/10/18/allegations-against-ubc-researchers%E2%80%99-study-on-insite-%E2%80%9Cwithout-merit%E2%80%9D-independent-reviewer/http://www.publicaffairs.ubc.ca/2011/10/18/allegations-against-ubc-researchers%E2%80%99-study-on-insite-%E2%80%9Cwithout-merit%E2%80%9D-independent-reviewer/http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898http://www.ncbi.nlm.nih.gov/pubmed?term=21497898
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    Urban Health Research InitiativeBC Centre for Excellence in HIV/[email protected]://uhri.cfenet.ubc.ca

    most Insite users reside. o illustrate the substantial di erencein the areas considered by Mr. Christians group and our team, we have included a gure (Figure 1, next page) that shows thesmall area considered in our study (outlined in green) and theDowntown Eastside LHA (outlined in red) that was used inthe REAL Women/DPNC report.

    Second, while this issue alone is su cient to explain thedi ering ndings, another critical methodological issue is thatthe REAL Women/DPNC report uses crude death counts ratherthan population-adjusted mortality rates. Te adjustmentfor changes in population size is generally a requirement inany analysis of death rates, given that failure to account forthe changing population at risk makes a presentation of thenumber of deaths very di cult to meaningfully interpret. In

    contrast, the Lancet study used annual population estimatefrom Statistics Canada to calculate annual overdose mortalirates. When one considers the much larger geographic arconsidered in the REAL Women/DPNC report, and the failureof the authors of the report to undertake basic adjustments fothe changing population at risk, it is not surprising they foundi erent results.

    Lastly, a major strength of theLancet study is the comparisoof changes in rates in two adjacent areas. Te REAL Women/DPNC critique does not acknowledge that we examinepopulation-adjusted death rates both in proximity to Insitand in the area of Vancouver that is greater than 500 metrefrom the facility as a quasi-control.

    Figure 3: Reduction in fatal overdose rates following the opening of Vancouvers SIFby census tract, January 2001 December 2005.

    Notes: Rate Difference (RD) repr esent s the absolute change in fatal overdos e rate (Rate pre-SIF Rate post-SIF)prior to and followi ng the opening of the sup ervis ed injection facility (SIF) on September 21, 2003. Thus,values greate r tha n one ind icate a red uction in the rate during the post -SIF period. Distanc e (d) wasme asured as the Euclid ean shortest path betwe en the centroid of each census trac t and the lo cation of the

    SIF. A nonlinear exp onentia l regr ession weighted by the total num ber of overd oses i n each census tract was conduct ed: the best t (shown in grey) was RD = 0.40 + 212.4e-4.17d , (R2 = 0.58).

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    Distance between Centroid of Census Tract and SIF (km)

    R a t e D i ff e r e n

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    Urban Health Research InitiativeBC Centre for Excellence in HIV/[email protected]://uhri.cfenet.ubc.ca

    2. e impact o policing: Te REAL Women/DPNC reportsuggests that a large-scale policing operation may account forthe reported decline in overdose deaths in theLancet study,and Mr. Christian alleges that our team was aware of thiscrackdown and committed an act of omission by failing tomention this crackdown in our study. We are confused by this suggestion for several reasons. First,documents on the City o Vancouvers website and a published evaluation o the police crackdown reveal clearly that this policinginitiative ended within weeks of Insites opening and was notongoing throughout the study period, as the authors of theREAL Women/DPNC report suggest. If this crackdown wasthe cause of the decline in overdoses after Insite opened, this would imply that: (1) the police crackdown led to an increasein overdose deaths in the area where Insite would later open;and (2) the subsequent decline in overdoses reported in the

    Lancet paper occurred because this policing initiative endeHowever, various reports and our published study of thcrackdown (Wood et al., Displacement o Canadas largestpublic illicit drug market in response to a police crackdownCMAJ , 2004; 170(10): 1151-1156) demonstrate that thispolice initiative displaced drug users away from the area wheInsite was subsequently located. Hence, it could be arguethat the displacement of drug users away from where Insi

    was located, prior to its opening, could have served to createconservative bias in theLancet study by reducing overdoses ithis geographic area before the facilitys opening. Tis in turn

    would have made it more di cult to demonstrate a decline inoverdose deaths after the facility opened. Second, we also wto point out that in his e ort to describe changes in policinpractices, Mr. Christian borrows heavily from an earlier DruPrevention of Canada report written by his co-author on the

    BC STATS

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    The area of focus of the

    Lancet study

    The area where 70% of daily Insite users live and wherethe 35% reduction in overdose rate was identi ed

    The area of focus of theREAL Women/DPNC report

    Local Health Area 162Downtown Eastside

    Sub Vancouver

    Figure 1. Comparison of geographic regions de ned as the area of interest inthe Lancet article by Marshall et al . (outlined in green) versus that referred to byChristian and colleagues (outlined in red, representing the Downtown EastsideLocal Health Area.

    http://vancouver.ca/fourpillars/newsletter/Jun04/data/mayorscolumn.htmhttp://vancouver.ca/fourpillars/newsletter/Jun04/data/mayorscolumn.htmhttp://www.vancouveragreement.ca/wp-content/uploads/ConfidentPolicing2004sm.pdfhttp://www.vancouveragreement.ca/wp-content/uploads/ConfidentPolicing2004sm.pdfhttp://www.ncbi.nlm.nih.gov/pubmed?term=15136548http://www.ncbi.nlm.nih.gov/pubmed?term=15136548http://www.ncbi.nlm.nih.gov/pubmed?term=15136548http://www.ncbi.nlm.nih.gov/pubmed?term=15136548http://www.vancouveragreement.ca/wp-content/uploads/ConfidentPolicing2004sm.pdfhttp://www.vancouveragreement.ca/wp-content/uploads/ConfidentPolicing2004sm.pdfhttp://vancouver.ca/fourpillars/newsletter/Jun04/data/mayorscolumn.htmhttp://vancouver.ca/fourpillars/newsletter/Jun04/data/mayorscolumn.htm
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    Urban Health Research InitiativeBC Centre for Excellence in HIV/[email protected]://uhri.cfenet.ubc.ca

    REAL Women/DPNC report, Colin Mangham. It shouldbe noted, however, that the organization that commissionedDr. Manghams report, the Royal Canadian Mounted Police,later acknowledged that Dr. Manghams work did not meetconventional academic standards. Not surprisingly, HealthCanadas Expert Advisory Committee on Supervised InjectionSite research chose to ignore Dr. Manghams report in theirreview of existing research on supervised injection sites.Further, during a recent Supreme Court of Canada hearingfocused on Insite, the lawyers representing the Governmentof Canada were forced to admit that they did not have any credible research to suggest that Insite was not working (i.e.,

    they did not o er Dr. Manghams work as evidence).3. Failure to state the nature o deaths: Mr. Christian allegesthat we included deaths that are not relevant to an evaluation of a supervised injecting facility. Below we respond directly to thisclaim. However, we rst wish to point out some problems withthe analysis of this issue as presented in the report co-authoredby Mr. Christian. Te REAL Women/DPNC report uses crudeVital Statistics data, which included all accidental poisoningsto de ne its estimate of overdose deaths, and it did not excludedeaths unlikely to be a ected by a supervised injecting facility (e.g., suicides, adverse e ects of drugs in therapeutic use). Wenote that the REAL Women/DPNC critique seeks to call intoquestion the Lancet papers ndings using these crude data,and then goes on to argue that the Lancet papers ndingscannot be relied upon because they use similarly unre neddeath counts. We would argue that you cannot have it both ways. Nevertheless, we acknowledge that determining a causeof overdose death, with certainty, can be di cult. Tis isparticularly true when trying to determine whether an overdose was caused by a particular drug or mode of use. Indeed, thereis a vast literature demonstrating that most overdose deathsare the result of poly substance use. We also note that theBC Coroners records do not routinely indicate the route of

    consumption, as attending paramedics and other emergency personnel have no way of determining with certainty the causeof death. However, to be absolutely clear, unlike the authors of the REAL Women/DPCN report, we did not use crude datafrom Vital Statistics, but rather worked closely with the BritishColumbia Coroners O ce to review toxicology results and

    other information contained in death records for all accidentapoisonings. Tese methods are described in detail in the Lancepaper. Unlike the approach used in the REAL Women/DPNCcritique, our method allowed us to exclude from our analysall deaths resulting from suicide and other causes that cousafely be assumed not to be amenable to change through supervised injecting facility. Mr. Christians teams failure exclude causes of death not amenable to reduction through supervised injecting facility (e.g., suicides) is another reason their disparate ndings.

    Finally, we note that it is possible to select out only thosrecords where injection drug use was noted in the Coroner

    case les. When this is done, the reduction in overdose deatis actually slightly higher. Whereas our report cites a 35reduction in overdose deaths in the area around Insite, wheonly those cases where a note in the le suggested that injectidrug use was implicated (e.g., a syringe was found near the boof the deceased), the reduction increases to 36%. Howevegiven the limitations in the data noted above, we felt that thitype of selection and exclusion based on inconsistently reportdata was a less conservative approach. We say this because amisclassi cation of causes of death would presumably seto diminish any real e ect of the supervised injecting facili

    whereas we felt that the alternative (i.e., selecting injectinrelated deaths based on incomplete information) could leave uopen to criticism that potentially relevant deaths were excludeRegardless, the above details demonstrate that the reduction overdose deaths in the area of interest around Insite was ndriven by non-injection overdose deaths.

    4. e impact o trends in heroin use: Te REAL Women/DPNC report includes claims that our group did notacknowledge, in a su cient manner, changing patterns oheroin use as a possible explanation for the observed decliin overdose deaths. Tis is false. On page 1434 of our study

    we state:

    We noted no di erences in the types of drugs implicated ideaths between the two periods within either area of interesFurther, data from a prospective cohort study of IDUs donin the same neighbourhood suggest that drug-use patternremained largely constant from 2001 to 2005.44

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    Urban Health Research InitiativeBC Centre for Excellence in HIV/[email protected]://uhri.cfenet.ubc.ca

    Te citation that accompanies these statements (44, above)refers to a report we released in 2009 (Drug Situation in Vancouver ) that displays the rate of daily heroin injectionamong injection drug users (IDU) participating in a cohortstudy of IDU in Vancouver. As shown in a gure from thatreport (below), although the proportion of IDU reportingdaily heroin use declined from 1998 to 2001, the proportionof IDU reporting daily heroin injecting remained stable from2001 to 2005 (i.e., the period considered in our Lancet study).

    We further note that, contrary to Mr. Christians claims,our Lancet paper goes to great lengths to acknowledgethat other factors may have contributed to the observeddecline in overdose deaths. In fact, the Discussion sectionof the manuscript is largely dedicated to a consideration of these issues. We believe a careful assessment of these otherfactors should lead a reasonable person to conclude that the

    programwhich was speci cally designed to reduce overdomortalitymay actually be the cause of the decline in overdomortality rates that occurred within 500 metres of the facilityIndeed, the Lancet study is consistent with reports from variouinternational settings indicating that supervised injection siteare associated with declining overdose mortality.

    In summary, we welcome academic debate, but we stand bthe data presented in our Lancet paper and note that, unlikethe report prepared by Mr. Christian and colleagues, our dat

    and methodological approach were subjected to extensive pereview and published in one of the worlds leading medic

    journals. Te results of our study demonstrate that Vancouverssupervised injection facility appears to have had a localized signi cant e ect on overdose mortality in the area of denseconcentrated injection drug use where the facility is located.

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    Figure 10a: Percent of Vancouver injection drug users reporting daily heroin injection, 19962007

    http://uhri.cfenet.ubc.ca/images/Documents/dsiv2009.pdfhttp://uhri.cfenet.ubc.ca/images/Documents/dsiv2009.pdfhttp://uhri.cfenet.ubc.ca/images/Documents/dsiv2009.pdfhttp://uhri.cfenet.ubc.ca/images/Documents/dsiv2009.pdf