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Dive into the research topics where Mia L. van der Kop is active.

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Featured researches published by Mia L. van der Kop.


JAMA | 2012

Association Between Use of Interferon Beta and Progression of Disability in Patients With Relapsing-Remitting Multiple Sclerosis

Afsaneh Shirani; Yinshan Zhao; Mohammad Ehsanul Karim; Charity Evans; Elaine Kingwell; Mia L. van der Kop; Joel Oger; Paul Gustafson; John Petkau; Helen Tremlett

CONTEXT Interferon beta is widely prescribed to treat multiple sclerosis (MS); however, its relationship with disability progression has yet to be established. OBJECTIVE To investigate the association between interferon beta exposure and disability progression in patients with relapsing-remitting MS. DESIGN, SETTING, AND PATIENTS Retrospective cohort study based on prospectively collected data (1985-2008) from British Columbia, Canada. Patients with relapsing-remitting MS treated with interferon beta (n = 868) were compared with untreated contemporary (n = 829) and historical (n = 959) cohorts. MAIN OUTCOME MEASURES The main outcome measure was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained score of 6 (requiring a cane to walk 100 m; confirmed at >150 days with no measurable improvement) on the Expanded Disability Status Scale (EDSS) (range, 0-10, with higher scores indicating higher disability). A multivariable Cox regression model with interferon beta treatment included as a time-varying covariate was used to assess the hazard of disease progression associated with interferon beta treatment. Analyses also included propensity score adjustment to address confounding by indication. RESULTS The median active follow-up times (first to last EDSS measurement) were as follows: for the interferon beta-treated cohort, 5.1 years (interquartile range [IQR], 3.0-7.0 years); for the contemporary control cohort, 4.0 years (IQR, 2.1-6.4 years); and for the historical control cohort, 10.8 years (IQR, 6.3-14.7 years). The observed outcome rates for reaching a sustained EDSS score of 6 were 10.8%, 5.3%, and 23.1% in the 3 cohorts, respectively. After adjustment for potential baseline confounders (sex, age, disease duration, and EDSS score), exposure to interferon beta was not associated with a statistically significant difference in the hazard of reaching an EDSS score of 6 when either the contemporary control cohort (hazard ratio, 1.30; 95% CI, 0.92-1.83; P = .14) or the historical control cohort (hazard ratio, 0.77; 95% CI, 0.58-1.02; P = .07) were considered. Further adjustment for comorbidities and socioeconomic status, where possible, did not change interpretations, and propensity score adjustment did not substantially change the results. CONCLUSION Among patients with relapsing-remitting MS, administration of interferon beta was not associated with a reduction in progression of disability.


BMJ Open | 2013

Mobile phone text messages for improving adherence to antiretroviral therapy (ART): a protocol for an individual patient data meta-analysis of randomised trials

Lawrence Mbuagbaw; Mia L. van der Kop; Richard Lester; Harsha Thirumurthy; Cristian Pop-Eleches; Chenglin Ye; Marek Smieja; Lisa Dolovich; Edward J Mills; Lehana Thabane

Objectives Our objectives were to analyse the effects of text messaging versus usual care in improving adherence to antiretroviral therapy (ART) in people living with HIV using individual patient data meta-analysis. Adjusted, sensitivity and subgroup analyses were conducted. Setting 3 randomised controlled trials conducted between 2010 and 2012 in rural and urban centres in Cameroon and Kenya (two studies) were used. Participants A total of 1166 participants were included in this analysis (Cameroon=200; Kenya=428 and 538). Primary and secondary outcomes The primary outcome was adherence to ART >95%. The secondary outcomes were mortality, losses to follow-up, transfers and withdrawals. Results Text messaging improved adherence to ART (OR 1.38; 95% CIs 1.08 to 1.78; p=0.012), even after adjustment for baseline covariates (OR 1.46; 95% CI 1.13 to 1.88; p=0.004). Primary education (compared with no formal education) was associated with a greater intervention effect on adherence (OR 1.65; 95% CI 1.10 to 2.48; p=0.016) and also showed a significant subgroup effect (p=0.039). In sensitivity analysis, our findings were robust to a modified threshold of adherence, multiple imputation for missing data and aggregate level data pooling, but not to fixed-effects meta-analyses using generalised estimation equations. There was a significant subgroup effect for long weekly (p=0.037), short weekly text messages (p=0.014) and interactive messaging (p=0.010). Text messaging did not significantly affect any of the secondary outcomes. Conclusions Text messaging has a significant effect on adherence to ART, and this effect is influenced by level of education, gender, timing (weekly vs daily) and interactivity. We recommend the use of interactive weekly text messaging to improve adherence to ART, which is most effective in those with at least a primary level of education.


Annals of Neurology | 2011

Neonatal and Delivery Outcomes in Women with Multiple Sclerosis

Mia L. van der Kop; Mark S. Pearce; Leanne Dahlgren; Anne Synnes; Dessa Sadovnick; Ana-Luiza Sayao; Helen Tremlett

To determine (1) whether the risk of adverse neonatal and delivery outcomes differs between mothers with and without multiple sclerosis (MS) and (2) whether risk is differentially associated with clinical factors of MS.


PLOS ONE | 2012

In-depth analysis of patient-clinician cell phone communication during the WelTel Kenya1 antiretroviral adherence trial.

Mia L. van der Kop; Sarah Karanja; Lehana Thabane; Carlo A. Marra; Michael H. Chung; Lawrence Gelmon; Joshua Kimani; Richard Lester

Background The WelTel Kenya1 trial demonstrated that text message support improved adherence to antiretroviral therapy (ART) and suppression of HIV-1 RNA load. The intervention involved sending weekly messages to patients inquiring how they were doing; participants were required to respond either that they were well or that there was a problem. Objectives 1) Describe problems participants identified through mobile phone support and reasons why participants did not respond to the messages; 2) investigate factors associated with indicating a problem and not responding; and 3) examine participant perceptions of the intervention. Design Secondary analysis of WelTel Kenya1 trial data. Methods Reasons participants indicated a problem or did not respond were extracted from the study log. Negative binomial regression was used to determine participant characteristics associated with indicating a problem and non-response. Data from follow-up questionnaires were used to describe participant perceptions of the intervention. Results Between 2007 and 2009, 271 participants generated 11,873 responses; 377 of which indicated a problem. Health issues were the primary reason for problem responses (72%). Rural residence (adjusted incidence rate ratio [IRR] 1.96; 95%CI 1.19–3.25; p = 0.009 and age were associated with indicating a problem (adjusted IRR 0.63 per increase in age group category; 95%CI 0.50–0.80; p<0.001). Higher educational level was associated with a decreased rate of non-response (adjusted IRR 0.81; 95%CI 0.69–0.94; p = 0.005). Of participants interviewed, 62% (n = 129) stated there were no barriers to the intervention; cell phone issues were the most common barrier. Benefits included reminding patients to take medication and promoting a feeling that “someone cares”. Conclusions The WelTel intervention enabled frequent communication between clinicians and patients during the WelTel Kenya1 trial. Many patients valued the service for the support it provided, with health-related concerns comprising the majority of problems identified by participants. Few sociodemographic characteristics were associated with participant engagement in the intervention.


BMJ Open | 2013

The effect of weekly short message service communication on patient retention in care in the first year after HIV diagnosis: study protocol for a randomised controlled trial (WelTel Retain)

Mia L. van der Kop; David I Ojakaa; Anik Patel; Lehana Thabane; Koki Kinagwi; Anna Mia Ekström; Kirsten Smillie; Sarah Karanja; Patricia Opondo Awiti; Edward J Mills; Carlo A. Marra; Lennie Bazira Kyomuhangi; Richard Lester

Introduction Interventions to improve retention in care after HIV diagnosis are necessary to optimise the timely initiation of antiretroviral therapy (ART) and HIV/AIDS control outcomes. Widespread mobile phone use presents new opportunities to engage patients in care. A randomised controlled trial (RCT), WelTel Kenya1, demonstrated that weekly text messages led to improved ART adherence and viral load suppression among those initiating ART. The aim of this study was to determine whether the WelTel intervention is an effective and cost-effective method of improving retention in care in the first year of care following HIV diagnosis. Methods and analysis WelTel Retain is an open, parallel group RCT that will be conducted at the Kibera Community Health Centre in Nairobi, Kenya. Over a 1-year period, we aim to recruit 686 individuals newly diagnosed with HIV who will be randomly allocated to an intervention or control arm (standard care) at a 1:1 ratio. Intervention arm participants will receive the weekly WelTel SMS ‘check-in’ to which they will be instructed to respond within 48 h. An HIV clinician will follow-up and triage any problems that are identified. Participants will be followed for 1 year, with a primary endpoint of retention in care at 12 months. Secondary outcomes include retention in stage 1 HIV care (patients return to the clinic to receive their first CD4 results) and timely ART initiation. Cost-effectiveness will be analysed through decision-analytic modelling. Ethics and dissemination Ethical approval has been obtained from the University of British Columbia and the African Medical and Research Foundation. This trial will test the effectiveness and cost-effectiveness of the WelTel intervention to engage patients during the first year of HIV care. Trial results and economic evaluation will help inform policy and practice on the use of WelTel in the early stages of HIV care. Trial registration ClinicalTrials.gov NCT01630304.


Journal of the Association of Nurses in AIDS Care | 2014

A Qualitative Study Investigating the Use of a Mobile Phone Short Message Service Designed to Improve HIV Adherence and Retention in Care in Canada (WelTel BC1)

Kirsten Smillie; Natasha Van Borek; Joshua Abaki; Neora Pick; Evelyn J. Maan; Karen Friesen; Rebecca Graham; Sarah Levine; Mia L. van der Kop; Richard Lester; Melanie Murray

&NA; Patient engagement in care and adherence to medication are critical to achieving the full benefits of antiretroviral therapy (ART) among people with HIV infection. A randomized controlled trial in Kenya, WelTelKenya1, showed that an interactive mobile phone text‐messaging intervention can improve adherence and viral load suppression. We conducted a pilot study to adapt the WelTel intervention for HIV‐infected clients (n = 25) at an HIV clinic in Vancouver, British Columbia. Between April and June 2012, we recruited five participants from five groups: youth (14–24 years), mature (≥50 years), English as a second language, remote (≥3 hours travel time to clinic), and nonsuppressed (CD4+ T cell count <200 cells/mm3 and viral load ≥250 copies/mL on two consecutive occasions). Participants described the intervention as a useful way to communicate with health care providers, thus increasing the ability to access services, report side effects, and attend appointments.


African Journal of AIDS Research | 2014

Mobile health for early retention in HIV care: a qualitative study in Kenya (WelTel Retain)

Kirsten Smillie; Natasha Van Borek; Mia L. van der Kop; Abigael Lukhwaro; Neville Li; Sarah Karanja; Anik Patel; David I Ojakaa; Richard Lester

Many people newly diagnosed with HIV are lost to follow-up before timely initiation of antiretroviral therapy (ART). A randomised controlled trial (RCT), WelTel Kenya1, demonstrated the effectiveness of the WelTel text messaging intervention to improve clinical outcomes among patients initiating ART. In preparation for WelTel Retain, an RCT that will evaluate the effect of the intervention to retain patients in care immediately following HIV diagnosis, we conducted an informative qualitative study with people living with HIV (n = 15) and healthcare providers (HCP) (n = 5) in October 2012. Study objectives included exploring the experiences of people living with HIV who have attempted to engage in HIV care, the use of cell phones in everyday life, and perceptions of communicating via text message with HCP. Participants were recruited through convenience sampling. Semi-structured, qualitative interviews were conducted and recorded, transcribed verbatim and analysed using NVivo software. Analysis was guided by the Theory of Reasoned Action and the Technology Acceptance Model. Results indicate that while individuals have many motivators for engaging in care after diagnosis, structural and individual barriers including poverty, depression and fear of stigma prevent them from doing so. All participants had access to a mobile phone, and most were comfortable communicating through text messages, or were willing to learn. Both people living with HIV and HCP felt that increased communication via the text messaging intervention has the potential to enable early identification of problems, leading to timely problem solving that may improve retention and engagement in care during the first year after diagnosis.


Neurology | 2013

Birth hospitalization in mothers with multiple sclerosis and their newborns

Ellen Lu; Yinshan Zhao; Feng Zhu; Mia L. van der Kop; Anne Synnes; Leanne Dahlgren; A. Dessa Sadovnick; Ana-Luiza Sayao; Helen Tremlett

Objective: To compare the duration of birth hospitalization in mothers with multiple sclerosis (MS) and their newborns relative to the general population and to investigate the impact of MS-related clinical factors on the length of birth hospitalization stays. Methods: Data from the British Columbia Perinatal Database Registry and the British Columbia MS database were linked in this retrospective cohort study. The duration of birth hospitalization in mothers with MS and their newborns (n = 432) were compared with a frequency-matched sample of the general population (n = 2,975) from 1998 to 2009. Clinical factors investigated included disease duration and disability, as measured by the Expanded Disability Status Scale. A multivariable model (generalized estimating equations) was used to analyze the association between MS and duration of birth hospitalization, adjusting for factors such as maternal age, diabetes, hypertension, and consecutive births to the same mother. Additional analyses included propensity score matching to further balance cohort characteristics. Results: Compared with the general population, the duration of birth hospitalization was not statistically or clinically different for mothers with MS or their newborns (median differences = +1.5 and +2.1 hours, respectively; adjusted p > 0.4). Lengths of birth hospitalization were not significantly associated with disease duration (adjusted p > 0.7) or level of disability (adjusted p > 0.5). Findings remained virtually unchanged after propensity score matching. Conclusions: Birth hospitalization has been understudied in women with MS. Contrary to existing studies, we found that MS was not associated with a longer birth hospitalization. This study provides assurance to expectant mothers with MS, their families, and health care providers.


American Journal of Epidemiology | 2016

Comparison of Statistical Approaches for Dealing With Immortal Time Bias in Drug Effectiveness Studies

Mohammad Ehsanul Karim; Paul Gustafson; John Petkau; Helen Tremlett; Afsaneh Shirani; Yinshan Zhao; Charity Evans; Elaine Kingwell; Mia L. van der Kop; Joel Oger; Anthony Traboulsee; Ana-Luiza Sayao; Virginia Devonshire; Stanley A. Hashimoto; John Hooge; Lorne F. Kastrukoff; D. Adams; D. Craig; S. Meckling; L. Daly; O. Hrebicek; D. Parton; K. Pope

In time-to-event analyses of observational studies of drug effectiveness, incorrect handling of the period between cohort entry and first treatment exposure during follow-up may result in immortal time bias. This bias can be eliminated by acknowledging a change in treatment exposure status with time-dependent analyses, such as fitting a time-dependent Cox model. The prescription time-distribution matching (PTDM) method has been proposed as a simpler approach for controlling immortal time bias. Using simulation studies and theoretical quantification of bias, we compared the performance of the PTDM approach with that of the time-dependent Cox model in the presence of immortal time. Both assessments revealed that the PTDM approach did not adequately address immortal time bias. Based on our simulation results, another recently proposed observational data analysis technique, the sequential Cox approach, was found to be more useful than the PTDM approach (Cox: bias = -0.002, mean squared error = 0.025; PTDM: bias = -1.411, mean squared error = 2.011). We applied these approaches to investigate the association of β-interferon treatment with delaying disability progression in a multiple sclerosis cohort in British Columbia, Canada (Long-Term Benefits and Adverse Effects of Beta-Interferon for Multiple Sclerosis (BeAMS) Study, 1995-2008).


BMJ Open | 2014

The effect of weekly text-message communication on treatment completion among patients with latent tuberculosis infection: study protocol for a randomised controlled trial (WelTel LTBI)

Mia L. van der Kop; Jasmina Memetovic; Anik Patel; Fawziah Marra; Mohsen Sadatsafavi; Jan Hajek; Kirsten Smillie; Lehana Thabane; Darlene Taylor; James D. Johnston; Richard Lester

Introduction Interventions to improve adherence to treatment for latent tuberculosis infection (LTBI) are necessary to improve treatment completion rates and optimise tuberculosis (TB) control efforts. The high prevalence of cell phone use presents opportunities to develop innovative ways to engage patients in care. A randomised controlled trial (RCT), WelTel Kenya1, demonstrated that weekly text messages improved antiretroviral adherence and clinical outcomes among patients initiating HIV treatment. The aim of this study is to determine whether the WelTel intervention can improve treatment completion among patients with LTBI and to evaluate the interventions cost-effectiveness. Methods and analysis This open, two-site, parallel RCT (WelTel LTBI) will be conducted at TB clinics in Vancouver and New Westminster, British Columbia, Canada. Over 2 years, we aim to recruit 350 individuals initiating a 9-month isoniazid regimen. Participants will be randomly allocated to an intervention or control (standard care) arm in a 1:1 ratio. Intervention arm participants will receive a weekly text-message ‘check-in’ to which they will be asked to respond within 48 h. A TB clinician will follow-up instances of non-response and problems that are identified. Participants will be followed until treatment completion (up to 12 months) or discontinuation. The primary outcome is self-reported treatment completion (taking ≥80% of doses within 12 months). Secondary outcomes include daily adherence (percentage of days participants used medication as prescribed) and time to treatment completion. Patient satisfaction with the intervention will be evaluated, and the interventions cost-effectiveness will be analysed through decision-analytic modelling. Ethics and dissemination Ethical approval has been obtained from the University of British Columbia. This trial will test the efficacy and cost-effectiveness of the WelTel intervention to improve treatment completion among patients with LTBI. Trial results and economic evaluation will help inform policy and practice on the use of WelTel in this population. Trial registration number ClinicalTrials.gov NCT01549457.

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Richard Lester

University of British Columbia

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Helen Tremlett

University of British Columbia

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Kirsten Smillie

University of British Columbia

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Yinshan Zhao

University of British Columbia

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Afsaneh Shirani

University of British Columbia

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Charity Evans

University of Saskatchewan

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Elaine Kingwell

University of British Columbia

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John Petkau

University of British Columbia

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Paul Gustafson

University of British Columbia

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