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A Comparison of Case-Based vs. Event-Based Methods for Detection of Signals of Disproportionality
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Abstracts / Annals of Epidemiology 22 (2012) 661e680
P50-S. Progestin-Only Contraceptive Use Is Independent Predictor of HPV Prevalence in Women Aged Over 35 Years T.R. Soong, M. Silver, K. Chang, W. Shen, R. Howard, A. Burke, P.E. Gravitt. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD Purpose: We assessed the associations of progestin-only contraceptive (POC) use and combined oral contraceptive (COC) use with cervical HPV prevalence in pre- and perimenopausal women aged over 35 years. Methods: Data came from a prospective study conducted in 530 women aged between 35 and 59 years with normal cervical cytology in the U.S. Prevalence ratios (PRs) with 95% confidence intervals (CIs) were estimated using generalized linear models with poisson function and robust variance. Results: Baseline prevalence of any HPV and high-risk (HR)-HPV were 16.4% and 6.4% respectively. Relative to never POC users, more than 5 years of cumulative POC use was associated with increased HPV prevalence after controlling for current and past sexual behaviors, days since last menstrual period, marital status and recent diagnoses of other sexually transmitted infections [adjusted prevalence ratio (aPR): 2.78 (95% CI: 1.55-4.97)]. No significant association was observed between last time of use of POCs and HPV prevalence. HPV detection was not associated with the recency or duration of COC use in our study population. Conclusions: Our findings suggest that long-term use of POCs is associated with increased risk of prevalent HPV infection independent of sexual behavior in older women. POC use may have impact on the natural history of HPV infection before development of clinical cervical disease.
P51-S. History of HIV Testing Among Men Who Have Sex With Men in a Chinese Metropolitan City L. Zhang, Y. Xiao, H. Qian, Y. Ruan, S.H. Vermund. Vanderbilt Institute for Global Health, Vanderbilt University School of Medicine, Nashville, TN Purpose: HIV testing is the getaway of prevention and care. However, the HIV testing rate is still low in men who have sex with men (MSM) in urban Chinese cities. We explored HIV testing behaviors and the associated factors among Chinese MSM. Methods: A total of 492 MSM were recruited using respondent driven sampling approach in Chongqing City in 2010. Demographic and behavioral data were collected by a computer-assisted self-interview approach. Blood specimens were tested for HIV and syphilis. Univariate and multivariate logistic regression analyses were performed to identify factors for past experience of HIV testing. Results: The adjusted HIV prevalence was 11.7% (95% confidence interval [CI]: 8.6%-11.6%) and syphilis prevalence was 4.7% (95% CI: 2.6%-7.3%). Fiftyeight percent of participants had ever taken a HIV test prior to the study, of whom 73% had taken within the last 12 months. MSM who had a college degree [adjusted odds ratio (AOR): 1.7; 95% CI: 1.2-2.6; P < 0.05] or those who preferred an insertive role over a receptive one in anal sex (AOR: 0.6; 95%CI: 0.36-0.93; P < 0.05) were more likely to take HIV tests. Fear of knowing a positive result, being afraid of discrimination if tested positive, and unwillingness of going to a clinic were the top 3 perceived barriers for taking a test; a low perceived risk of HIV infection, not knowing where to take testing and concern about being found out positive were the top 3 actual reasons for not taking a HIV test. Conclusion: Mental and psychological supports along with education are urgently needed to improve HIV testing among Chinese MSM.
Methods P52. Reaching Under/Never Screened Populations Using an Online Survey B. Filsinger, D. Gesink, A. Mihic, N. Kreiger. Cancer Care Ontario/Dalla Lana School of Public Health, University of Toronto, Toronto, ON Purpose: Participation rates for breast, cervical, and colon cancer screening in Ontario are below targeted levels. By engaging populations that do not typically participate in cancer screening and identifying the barriers and
facilitators associated with screening behaviours, targeted programs and interventions can be developed at the community level. Methods: Data is being collected from a volunteer sample of the Ontario population using a cross-sectional study design. Participants complete a short, online survey exploring cancer screening habits. Social media has been used to promote the survey through partnerships with community and government organizations (the YMCA, Ontario Public Libraries, etc.), in addition to traditional methods. Results: In the first three months, 1342 individuals (18 to 90 years of age, median 51 years) have completed the on-going survey. The sample is 88.9% Caucasian and females account for 82.9%. Preliminary results indicate the need for different or easier screening tests (27.8% of respondents). Doctors are not suggesting cancer screening (17.6%) and individuals cannot schedule time to take the tests (15.5%). In addition, 15.7% would start cancer screening with the appearance of symptoms. Conclusion: The online nature of the survey allows instant results and tailoring of participation strategies. This information has been used to form new partnerships with religious and ethnic organizations in minority groups and underrepresented areas. Supplying community partners with local response rates has increased partner ownership and re-doubled their efforts.
P53. A Comparison of Case-Based vs. Event-Based Methods for Detection of Signals of Disproportionality N. Kellier, Q. Zhang, I. Lipkovich, K. Hornbuckle. Eli Lilly and Company, Indianapolis, IN Purpose: When performing surveillance for manufacturing related adverse events(AEs), oftentimes there are multiple AEs and batch(lot) numbers in one case report. The objective of this study is to evaluate casebased(CB) vs. event-based(EB) frequencies when detecting signals of disproportionality, using relative risk(RR), proportional reporting ratio(PRR), and shrinking RR based on the Empirical Bayes Poisson-gamma model (EBGM and EB05). Method: Each method (RR, PRR, EBGM, EB05) was evaluated using CB and EB counts to identify signals of disproportionality using simulated data under the null (no true signal) and under alternative hypothesis ( one true signal). Three scenarios were considered for each case with multiple AEs: 1) one known batch(lot) number; 2) multiple known batch(lot) numbers; 3) scenario 2 plus unknown batch(lot) numbers. Results: Under the null hypothesis, the EB estimations produced a lower number of false positives(FP) for both the RR and PRR (CB: > 170 signals; EB: < 120 signals; p-value<0.0001). Under the alternative hypothesis, EB and CB estimations had similar sensitivity (1 signal: approx.1; 40 signals: approx 0.8), however, EB performed better in terms of the number of FPs (CB: 1 signal, approx.130 FP, 40 signals: approx. 100 FP; EB: 1 signal, approx.70 FP, 40 signals, approx. 60 FP). Conclusion: When comparing results for CB and EB units of analysis, although the sensitivity for each method was similar, the number of FPs differed significantly.
P54. Validation of Persian Version of the Prolaps E QualityeOfLife Questionnaire (P-QOL) N. Morovatdar, M. Nojomi, G. Alessandro Digesu, V. Khullar, L. Haghighi, M. Alirezaei, S. Swift. Department of community Medicine, School of Medicine, Tehran University of Medical Sciences, Crossroad of Hemmat and Chamran Expressways,15875-6171 Tehran, Iran Purpose: The aim of this study was to evaluate the validity and reliability of a Persian translation of the Prolapse Quality-of-Life (P-QOL) questionnaire in women with pelvic organ prolapse (POP). Methods: One hundred and twenty-four women with POP symptoms and 125 asymptomatic women were studied. The asymptomatic group was used for discriminant validity. Results: Seventy-two percent (89/124) of the symptomatic women had stage 2 POP while 86% (108/125) of the asymptomatic women had a stage <2 POP. All domains of the Persian P-QOL have a Cronbach's alpha coefficient greater than 0.7 (0.78e0.97) and were significantly different between symptomatic and asymptomatic women indicating a good discriminant validity (<0.01). The testeretest reliability confirmed a highly significant correlation. All items of PQOL questionnaire correlated significantly with the objective vaginal examination findings (construct validity) except for personal relationship and emotions. Conclusion: The Persian version of the P-QOL is a valid and reliable tool to assess QOL of women with POP.
Abstracts / Annals of Epidemiology 22 (2012) 661e680
P50-S. Progestin-Only Contraceptive Use Is Independent Predictor of HPV Prevalence in Women Aged Over 35 Years T.R. Soong, M. Silver, K. Chang, W. Shen, R. Howard, A. Burke, P.E. Gravitt. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD Purpose: We assessed the associations of progestin-only contraceptive (POC) use and combined oral contraceptive (COC) use with cervical HPV prevalence in pre- and perimenopausal women aged over 35 years. Methods: Data came from a prospective study conducted in 530 women aged between 35 and 59 years with normal cervical cytology in the U.S. Prevalence ratios (PRs) with 95% confidence intervals (CIs) were estimated using generalized linear models with poisson function and robust variance. Results: Baseline prevalence of any HPV and high-risk (HR)-HPV were 16.4% and 6.4% respectively. Relative to never POC users, more than 5 years of cumulative POC use was associated with increased HPV prevalence after controlling for current and past sexual behaviors, days since last menstrual period, marital status and recent diagnoses of other sexually transmitted infections [adjusted prevalence ratio (aPR): 2.78 (95% CI: 1.55-4.97)]. No significant association was observed between last time of use of POCs and HPV prevalence. HPV detection was not associated with the recency or duration of COC use in our study population. Conclusions: Our findings suggest that long-term use of POCs is associated with increased risk of prevalent HPV infection independent of sexual behavior in older women. POC use may have impact on the natural history of HPV infection before development of clinical cervical disease.
P51-S. History of HIV Testing Among Men Who Have Sex With Men in a Chinese Metropolitan City L. Zhang, Y. Xiao, H. Qian, Y. Ruan, S.H. Vermund. Vanderbilt Institute for Global Health, Vanderbilt University School of Medicine, Nashville, TN Purpose: HIV testing is the getaway of prevention and care. However, the HIV testing rate is still low in men who have sex with men (MSM) in urban Chinese cities. We explored HIV testing behaviors and the associated factors among Chinese MSM. Methods: A total of 492 MSM were recruited using respondent driven sampling approach in Chongqing City in 2010. Demographic and behavioral data were collected by a computer-assisted self-interview approach. Blood specimens were tested for HIV and syphilis. Univariate and multivariate logistic regression analyses were performed to identify factors for past experience of HIV testing. Results: The adjusted HIV prevalence was 11.7% (95% confidence interval [CI]: 8.6%-11.6%) and syphilis prevalence was 4.7% (95% CI: 2.6%-7.3%). Fiftyeight percent of participants had ever taken a HIV test prior to the study, of whom 73% had taken within the last 12 months. MSM who had a college degree [adjusted odds ratio (AOR): 1.7; 95% CI: 1.2-2.6; P < 0.05] or those who preferred an insertive role over a receptive one in anal sex (AOR: 0.6; 95%CI: 0.36-0.93; P < 0.05) were more likely to take HIV tests. Fear of knowing a positive result, being afraid of discrimination if tested positive, and unwillingness of going to a clinic were the top 3 perceived barriers for taking a test; a low perceived risk of HIV infection, not knowing where to take testing and concern about being found out positive were the top 3 actual reasons for not taking a HIV test. Conclusion: Mental and psychological supports along with education are urgently needed to improve HIV testing among Chinese MSM.
Methods P52. Reaching Under/Never Screened Populations Using an Online Survey B. Filsinger, D. Gesink, A. Mihic, N. Kreiger. Cancer Care Ontario/Dalla Lana School of Public Health, University of Toronto, Toronto, ON Purpose: Participation rates for breast, cervical, and colon cancer screening in Ontario are below targeted levels. By engaging populations that do not typically participate in cancer screening and identifying the barriers and
facilitators associated with screening behaviours, targeted programs and interventions can be developed at the community level. Methods: Data is being collected from a volunteer sample of the Ontario population using a cross-sectional study design. Participants complete a short, online survey exploring cancer screening habits. Social media has been used to promote the survey through partnerships with community and government organizations (the YMCA, Ontario Public Libraries, etc.), in addition to traditional methods. Results: In the first three months, 1342 individuals (18 to 90 years of age, median 51 years) have completed the on-going survey. The sample is 88.9% Caucasian and females account for 82.9%. Preliminary results indicate the need for different or easier screening tests (27.8% of respondents). Doctors are not suggesting cancer screening (17.6%) and individuals cannot schedule time to take the tests (15.5%). In addition, 15.7% would start cancer screening with the appearance of symptoms. Conclusion: The online nature of the survey allows instant results and tailoring of participation strategies. This information has been used to form new partnerships with religious and ethnic organizations in minority groups and underrepresented areas. Supplying community partners with local response rates has increased partner ownership and re-doubled their efforts.
P53. A Comparison of Case-Based vs. Event-Based Methods for Detection of Signals of Disproportionality N. Kellier, Q. Zhang, I. Lipkovich, K. Hornbuckle. Eli Lilly and Company, Indianapolis, IN Purpose: When performing surveillance for manufacturing related adverse events(AEs), oftentimes there are multiple AEs and batch(lot) numbers in one case report. The objective of this study is to evaluate casebased(CB) vs. event-based(EB) frequencies when detecting signals of disproportionality, using relative risk(RR), proportional reporting ratio(PRR), and shrinking RR based on the Empirical Bayes Poisson-gamma model (EBGM and EB05). Method: Each method (RR, PRR, EBGM, EB05) was evaluated using CB and EB counts to identify signals of disproportionality using simulated data under the null (no true signal) and under alternative hypothesis ( one true signal). Three scenarios were considered for each case with multiple AEs: 1) one known batch(lot) number; 2) multiple known batch(lot) numbers; 3) scenario 2 plus unknown batch(lot) numbers. Results: Under the null hypothesis, the EB estimations produced a lower number of false positives(FP) for both the RR and PRR (CB: > 170 signals; EB: < 120 signals; p-value<0.0001). Under the alternative hypothesis, EB and CB estimations had similar sensitivity (1 signal: approx.1; 40 signals: approx 0.8), however, EB performed better in terms of the number of FPs (CB: 1 signal, approx.130 FP, 40 signals: approx. 100 FP; EB: 1 signal, approx.70 FP, 40 signals, approx. 60 FP). Conclusion: When comparing results for CB and EB units of analysis, although the sensitivity for each method was similar, the number of FPs differed significantly.
P54. Validation of Persian Version of the Prolaps E QualityeOfLife Questionnaire (P-QOL) N. Morovatdar, M. Nojomi, G. Alessandro Digesu, V. Khullar, L. Haghighi, M. Alirezaei, S. Swift. Department of community Medicine, School of Medicine, Tehran University of Medical Sciences, Crossroad of Hemmat and Chamran Expressways,15875-6171 Tehran, Iran Purpose: The aim of this study was to evaluate the validity and reliability of a Persian translation of the Prolapse Quality-of-Life (P-QOL) questionnaire in women with pelvic organ prolapse (POP). Methods: One hundred and twenty-four women with POP symptoms and 125 asymptomatic women were studied. The asymptomatic group was used for discriminant validity. Results: Seventy-two percent (89/124) of the symptomatic women had stage 2 POP while 86% (108/125) of the asymptomatic women had a stage <2 POP. All domains of the Persian P-QOL have a Cronbach's alpha coefficient greater than 0.7 (0.78e0.97) and were significantly different between symptomatic and asymptomatic women indicating a good discriminant validity (<0.01). The testeretest reliability confirmed a highly significant correlation. All items of PQOL questionnaire correlated significantly with the objective vaginal examination findings (construct validity) except for personal relationship and emotions. Conclusion: The Persian version of the P-QOL is a valid and reliable tool to assess QOL of women with POP.