Browsing by Author "Peng, Mingkai"

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    Blood pressure at age 60–65 versus age 70–75 and vascular dementia: a population based observational study
    (2017-10-27) Peng, Mingkai; Chen, Guanmin; Tang, Karen L; Quan, Hude; Smith, Eric E; Faris, Peter; Hachinski, Vladimir; Campbell, Norm R C
    Abstract Background Vascular dementia (VaD) is the second most common form of dementia. However, there were mixed evidences about the association between blood pressure (BP) and risk of VaD in midlife and late life and limited evidence on the association between pulse pressure and VaD. Methods This is a population-based observational study. 265,897 individuals with at least one BP measurement between the ages of 60 to 65 years and 211,116 individuals with at least one BP measurement between the ages of 70 to 75 years were extracted from The Health Improvement Network in United Kingdom. Blood pressures were categorized into four groups: normal, prehypertension, stage 1 hypertension, and stage 2 hypertension. Cases of VaD were identified from the recorded clinical diagnoses. Multivariable survival analysis was used to adjust other confounders and competing risk of death. All the analysis were stratified based on antihypertensive drug use status. Multiple imputation was used to fill in missing values. Results After accounting for the competing risk of death and adjustment for potential confounders, there was an association between higher BP levels in the age 60–65 cohort with the risk of developing VaD (hazard ratio [HR] 1.53 (95% confidence interval: 1.04, 2.25) for prehypertension, 1.90 (1.30, 2.78) for stage 1 hypertension, and 2.19 (1.48, 3.26) for stage 2 hypertension) in the untreated group. There was no statistically significant association between BP levels and VaD in the treated group in the age 60–65 cohort and age 70–75 cohort. Analysis on Pulse Pressure (PP) stratified by blood pressure level showed that PP was not independently associated with VaD. Conclusion High BP between the ages of 60 to 65 years is a significant risk for VaD in late midlife. Greater efforts should be placed on early diagnosis of hypertension and tight control of BP for hypertensive patients for the prevention of VaD.
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    Development and validation of data quality rules in administrative health data using association rule mining
    (2020-04-25) Peng, Mingkai; Lee, Sangmin; D’Souza, Adam G; Doktorchik, Chelsea T A; Quan, Hude
    Abstract Background Data quality assessment presents a challenge for research using coded administrative health data. The objective of this study is to develop and validate a set of coding association rules for coded diagnostic data. Methods We used the Canadian re-abstracted hospital discharge abstract data coded in International Classification of Disease, 10th revision (ICD-10) codes. Association rule mining was conducted on the re-abstracted data in four age groups (0–4, 20–44, 45–64; ≥ 65) to extract ICD-10 coding association rules at the three-digit (category of diagnosis) and four-digit levels (category of diagnosis with etiology, anatomy, or severity). The rules were reviewed by a panel of 5 physicians and 2 classification specialists using a modified Delphi rating process. We proposed and defined the variance and bias to assess data quality using the rules. Results After the rule mining process and the panel review, 388 rules at the three-digit level and 275 rules at the four-digit level were developed. Half of the rules were from the age group of ≥65. Rules captured meaningful age-specific clinical associations, with rules at the age group of ≥65 being more complex and comprehensive than other age groups. The variance and bias can identify rules with high bias and variance in Alberta data and provides directions for quality improvement. Conclusions A set of ICD-10 data quality rules were developed and validated by a clinical and classification expert panel. The rules can be used as a tool to assess ICD-coded data, enabling the monitoring and comparison of data quality across institutions, provinces, and countries.
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    Evaluation of the Effect of Hospital and Physician Factors on Likelihood of Revision After Mid-Urethral Sling Placement
    (2020-01) Brennand, Erin Alexandra; Quan, Hude; Metcalfe, Amy; Peng, Mingkai; McCaughey, Deirdre
    Objective: To estimate rates of revision surgery after insertion of mesh midurethral slings (MUS) and explore if healthcare attributes such as physician specialty, annual operative volume, or hospital type are risk factors for this outcome. Methods: This study used a population-based retrospective cohort of women who underwent MUS insertion over a 13-year interval (2004–2017) in Alberta, Canada. The main outcome was subsequent surgery for revision of MUS, defined by a composite of surgical procedures. Exposures included annual number of MUS procedures performed by the surgeon, facility type, surgeon specialty, patient age, and concomitant prolapse repair. Mixed-effects logistic regression utilizing linear spines was used to test the a priori hypothesis that annual surgical volume would be inversely related in a non-linear fashion to risk of revision. Results: In a cohort of 19,511 women, cumulative rates of revision surgery were 3.36% (95% CI 3.06–3.68) at 5 years and 4.57% (95% CI 4.00–5.21) at 10 years. The first year after MUS insertion was the most vulnerable window, with 0.39% (95% CI 0.31–0.49) undergoing revision within 30 days and 2.05% (95% CI 1.85–2.26) within a year. Concomitant prolapse repairs (OR = 1.24, 95% CI 1.04–1.48) and surgeon’s annual volume were associated with revision. After 50 cases per year, odds of revision declined with each additional case (OR = 0.991 per case, 95% CI 0.983–0.999; OR = 0.91 per 10 cases, 95% CI 0.84–0.98) and plateaued at 110 cases per year. Surgeon specialty, hospital type, and patient age were not associated with outcome. Conclusions and relevance: Within 10 years, nearly 1 in 20 women underwent revision surgery after MUS insertion. Physician annual surgical volume appears to be a risk factor, with a decline in risk of revision surgery occurring at an annual threshold of >50 cases. Given that annual case volume is a potentially modifiable risk factor, development of policies regarding minimum caseload parameters for surgeons performing MUS procedures may hold potential to improve the quality of MUS surgery.
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    Exploring data reduction strategies in the analysis of continuous pressure imaging technology
    (2023-03-01) Peng, Mingkai; Southern, Danielle A.; Ocampo, Wrechelle; Kaufman, Jaime; Hogan, David B.; Conly, John; Baylis, Barry W.; Stelfox, Henry T.; Ho, Chester; Ghali, William A.
    Abstract Background Science is becoming increasingly data intensive as digital innovations bring new capacity for continuous data generation and storage. This progress also brings challenges, as many scientific initiatives are challenged by the shear volumes of data produced. Here we present a case study of a data intensive randomized clinical trial assessing the utility of continuous pressure imaging (CPI) for reducing pressure injuries. Objective To explore an approach to reducing the amount of CPI data required for analyses to a manageable size without loss of critical information using a nested subset of pressure data. Methods Data from four enrolled study participants excluded from the analytical phase of the study were used to develop an approach to data reduction. A two-step data strategy was used. First, raw data were sampled at different frequencies (5, 30, 60, 120, and 240 s) to identify optimal measurement frequency. Second, similarity between adjacent frames was evaluated using correlation coefficients to identify position changes of enrolled study participants. Data strategy performance was evaluated through visual inspection using heat maps and time series plots. Results A sampling frequency of every 60 s provided reasonable representation of changes in interface pressure over time. This approach translated to using only 1.7% of the collected data in analyses. In the second step it was found that 160 frames within 24 h represented the pressure states of study participants. In total, only 480 frames from the 72 h of collected data would be needed for analyses without loss of information. Only ~ 0.2% of the raw data collected would be required for assessment of the primary trial outcome. Conclusions Data reduction is an important component of big data analytics. Our two-step strategy markedly reduced the amount of data required for analyses without loss of information. This data reduction strategy, if validated, could be used in other CPI and other settings where large amounts of both temporal and spatial data must be analysed.
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    Increasing incidence of syphilis among patients engaged in HIV care in Alberta, Canada: a retrospective clinic-based cohort study
    (2018-03-13) Lang, Raynell; Read, Ron; Krentz, Hartmut B; Ramazani, Soheil; Peng, Mingkai; Gratrix, Jennifer; Gill, M. J
    Abstract Background Syphilis is a global health concern disproportionately affecting HIV-infected populations. In Alberta, Canada, the incidence of syphilis in the general population has recently doubled with 25% of these infections occurring in HIV-infected patients. The Southern Alberta HIV Clinic (SAC) and Calgary STI Program (CSTI) analyzed the epidemiologic characteristics of incident syphilis infections in our well-defined, HIV-infected population over 11 years. Methods Since 2006, as routine practice of both the Southern Alberta Clinic (SAC) and Calgary STI Programs (CSTI), syphilis screening has accompanied HIV viral load measures every four months. All records of patients who, while in HIV care, either converted from being syphilis seronegative to a confirmed seropositive or were re-infected as evidenced by a four-fold increase in rapid plasma reagin (RPR) after past successful treatment, were reviewed. Results Incident syphilis was identified 249 times in 194 HIV-infected individuals. There were 36 individuals with repeated infections (28.5% of episodes). Following a prior decline in annual incident syphilis rates, the rates have tripled from 8.08/1000 patient-years (95% confidence interval (CI): 4.14–14.75) in 2011, to 27.04 per 1000 person-years (95% CI: 19.45–36.76) in 2016. Half of the syphilis episodes were asymptomatic. Patients diagnosed with syphilis were twice as likely not to be taking ART and had a higher likelihood of having plasma HIV RNA viral loads > 1000 copies/mL (19%). Incident syphilis was seen predominantly in Caucasians (72%, P < 0.001), males (94%, P < 0.001) and men who have sex with men (MSM) as their HIV risk activity (75%, P < 0.001). Conclusions We have highlighted the importance of a regular syphilis screening program in HIV-infected individuals demonstrated by increasing rates of incident syphilis in our region. Targeted preventative strategies should be directed towards HIV-infected populations identified at highest risk, including; MSM, prior alcohol abuse, prior recreational drug use and those with prior syphilis diagnoses.
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    Validation of a case definition for depression in administrative data against primary chart data as a reference standard
    (2019-01-07) Doktorchik, Chelsea; Patten, Scott; Eastwood, Cathy; Peng, Mingkai; Chen, Guanmin; Beck, Cynthia A; Jetté, Nathalie; Williamson, Tyler; Quan, Hude
    Abstract Background Because the collection of mental health information through interviews is expensive and time consuming, interest in using population-based administrative health data to conduct research on depression has increased. However, there is concern that misclassification of disease diagnosis in the underlying data might bias the results. Our objective was to determine the validity of International Classification of Disease (ICD)-9 and ICD-10 administrative health data case definitions for depression using review of family physician (FP) charts as the reference standard. Methods Trained chart reviewers reviewed 3362 randomly selected charts from years 2001 and 2004 at 64 FP clinics in Alberta (AB) and British Columbia (BC), Canada. Depression was defined as presence of either: 1) documentation of major depressive episode, or 2) documentation of specific antidepressant medication prescription plus recorded depressed mood. The charts were linked to administrative data (hospital discharge abstracts and physician claims data) using personal health numbers. Validity indices were estimated for six administrative data definitions of depression using three years of administrative data. Results Depression prevalence by chart review was 15.9–19.2% depending on year, region, and province. An ICD administrative data definition of ‘2 depression claims with depression ICD codes within a one-year window OR 1 discharge abstract data (DAD) depression diagnosis’ had the highest overall validity, with estimates being 61.4% for sensitivity, 94.3% for specificity, 69.7% for positive predictive value, and 92.0% for negative predictive value. Stratification of the validity parameters for this case definition showed that sensitivity was fairly consistent across groups, however the positive predictive value was significantly higher in 2004 data compared to 2001 data (78.8 and 59.6%, respectively), and in AB data compared to BC data (79.8 and 61.7%, respectively). Conclusions Sensitivity of the case definition is often moderate, and specificity is often high, possibly due to undercoding of depression. Limitations to this study include the use of FP charts data as the reference standard, given the potential for missed or incorrect depression diagnoses. These results suggest that that administrative data can be used as a source of information for both research and surveillance purposes, while remaining aware of these limitations.