Population-based Sampling Methods Research Articles

Insomnia symptom subtypes and manifestations of prodromal neurodegeneration: a population-based study in the Canadian Longitudinal Study on Aging.

To identify the association between insomnia symptoms and signs of prodromal neurodegeneration, including an analysis of potential differences between sleep-onset and sleep-maintenance insomnia. We included those aged 45-85 years, living in 1 of 10 Canadian provinces between 2012 and 2015 (at the baseline), recruited via 3 population-based sampling methods. Insomnia symptoms were assessed using questions adapted/modified from the Pittsburgh Sleep Quality Index. A panel of potential prodromal neurodegenerative markers including self-reported symptoms and objective gait motor, cognitive, and autonomic variables were assessed cross sectionally. We compared those who endorsed insomnia symptoms ≥ 3 times per week to controls, adjusting for age, sex, and education via logistic regression. Overall, 2,051/30,097 people screened positive for sleep-onset insomnia alone and 4,333 for sleep-maintenance insomnia alone, while 2,371 endorsed both subtypes. On objective gait tests, participants with sleep-onset insomnia, but not sleep-maintenance insomnia, had worse balance (odds ratio [OR] = 1.33, 95% confidence interval = [1.16, 1.52]) and slower gait speed (OR = 1.52 [1.34, 1.73]). Although participants with any insomnia subtype endorsed more motor symptoms, these were more severe in those with sleep-onset insomnia (OR onset vs maintenance = 1.13 [1.07, 1.18]). On objective cognitive tests, those with sleep-maintenance insomnia scored normally. However, participants with sleep-onset insomnia performed worse on tests of verbal fluency (OR = 1.24 [1.06, 1.43]), immediate memory (OR = 1.23 [1.08, 1.41]), and prospective memory task (OR = 1.29 [1.11, 1.50]). The sleep-onset insomnia group also had lower heart rate variability (OR = 1.23 [1.07, 1.43]). Secondary analyses found generally similar results in young vs older age of insomnia development. Compared to maintenance insomnia, those with sleep-onset insomnia have more motor, cognitive, and autonomic signs/symptoms. When evaluating neurodegenerative risk, differentiating insomnia subtypes may increase precision. Yao CW, Pelletier A, Fereshtehnejad S-M, Cross N, Dang-Vu T, Postuma RB. Insomnia symptom subtypes and manifestations of prodromal neurodegeneration: a population-based study in the Canadian Longitudinal Study on Aging. J Clin Sleep Med. 2022;18(2):345-359.

525 A population-based study of phenoconversion to parkinsonism from REM sleep behavior: a Population-based Study in the CLSA

Abstract Introduction To date, studies have estimated the phenoconversion rate from sleep clinics, using polysomnography proven RBD. However, no population-based estimates have been reported, testing to what degree possible RBD, screened by questionnaire is associated with increased risk of neurodegeneration. Methods We included those aged 45–85 years, living in one of 10 Canadian provinces in between 2012–2015 (at the baseline), recruited via three population-based sampling methods. Dream enactment behavior/possible RBD was screened using the RBD1Q single question-questionnaire. De-novo parkinsonism was defined as free of pre-existing diagnosis at the baseline with a ‘new’ diagnosis at the follow-up (205–2019). Relative risk (log-binomial regression), hazard ratio (Cox regression), incidence rate (Poisson regression) between the affected group and the symptom naïve group were assessed, adjusting for age and sex (and total years of education and language). Results Overall, 58 participants phenoconverted into parkinsonism and 53 into dementia at the follow-up (mean intervals=3.06±0.37 years). Participants with dream enactment behavior had 2.75 times higher risk to phenoconvert into parkinsonism than the symptom-free. Similarly, those with dream enactment behavior at the baseline possessed higher risk to screening positive of parkinsonism. No difference in time to phenoconversion was found between groups, The results remained robust after excluding non-RBD related symptoms, such as apnea and non-REM sleep parasomnia. Conclusion Compared to symptom-free, those with pRBD had higher risk to developing parkinsonism in near future. Support (if any):

Population-Based Survey Methods for Reaching Adolescent and Young Adult Survivors of Pediatric Cancer and Their Parents.

Contacting childhood cancer survivors (CCS) to assess reasons for declining receipt of follow-up care after treatment is difficult and participation in surveys may be low, resulting in biased results. We sought to demonstrate effective recruitment and population-based sampling methods to improve response and minimize bias. Four hundred and seventy CCS diagnosed between 2000 and 2007 at two hospitals in Los Angeles County were selected from the California Cancer Registry and were 15-25 years of age at the time of interview. Surveys of survivors and their parents were completed by multiple methods including mail, online, and telephone. Effectiveness of "plain" versus "designer" formatting of study materials was tested. Variables associated with response were analyzed using univariate and multivariable methods. Effort required for recruitment was quantified. Fifty percent of survivors (n = 235) and 36.5% of parents (n = 171) responded, and there were 160 parent-child dyads among them. Among located survivors, 61% participated. Response was higher for women, parents of younger survivors, and those from higher socioeconomic status areas. Among Hispanics, no variables were related to response. More effort was required to reach men and older survivors, but efforts beyond 15 calls and 7 remailings were unproductive. Formatting (i.e., plain vs. designer) did not affect response. Efforts to reach survivors must include multiple methods to be successful. Use of an intensive recruitment strategy and population-based sample resulted in a largely representative sample of CCS, especially for Hispanics. Expensive design efforts had little effect on recruitment, suggesting that plainer materials are sufficient. This example may inform similar studies.

Childhood Adversities Associated with Poor Adult Mental Health Outcomes in Older Homeless Adults: Results From the HOPE HOME Study

To examine whether childhood adversity is associated with depressive symptoms, suicide attempts, or psychiatric hospitalization. History of seven childhood adversities (physical neglect, verbal abuse, physical abuse, sexual abuse, parental death, parental incarceration, and child welfare system placement) was gathered through in-person interviews. Multivariate models examined associations between history of childhood adversities and moderate to severe depressive symptoms, lifetime history of suicide attempt, or lifetime history of psychiatric hospitalization. The study enrolled 350 homeless adults, aged 50 and older, in Oakland, California, using population-based sampling methods. Moderate to severe depressive symptoms were measured on a Center for Epidemiologic Studies-Depression Scale (≥22), self-reported lifetime history of suicide attempt, and self-reported lifetime history of psychiatric hospitalization. Participants with exposure to one childhood adversity had elevated odds of reporting moderate to severe depressive symptoms (adjusted odds ratio [AOR]: 2.0; 95% confidence interval [CI]: 1.1-3.7) and lifetime history of suicide attempt (AOR: 4.6; 95% CI: 1.0-21.6) when compared with those who had none; the odds of these two outcomes increased with exposure to additional childhood adversities. Participants with four or more childhood adversities had higher odds of having a lifetime history of psychiatric hospitalization (AOR: 7.1; 95% CI: 2.8-18.0); no increase with fewer adversities was found. Childhood adversities are associated with poor mental health outcomes among older homeless adults. Clinicians should collect information about childhood adversities among this high-risk population to inform risk assessment and treatment recommendations.

Population-based sampling methods for geological well testing

In this paper, the application of a population-based sampling algorithm, i.e., differential evolution, in the geological well testing of a multi-layered faulted reservoir model is discussed. In this sense, the available multiple well test datasets are used to calibrate the geological model parameters rather than fitting simplified analytical models. In the exercise studied in this paper, the parameter space includes a range of geostatistical, petrophysical, and structural parameters. The differential evolution algorithm starts with an initial random population from the ranges of input variables and progresses with successive evaluation of the static models’ transient tests. The static models’ input parameters are perturbed to generate new populations, which can finally match the truth model well test derivative with lower misfits. The ensemble of population models (samples) along with the misfit values are used to highlight the value of well test data in reducing the uncertainty in the parameter space. A Bayesian framework is employed to implement the Markov chain Monte Carlo (McMC) methods to estimate the posterior distributions of the parameters. The results are confirmed by the sample-based Sobol sensitivity indices, which rank the influential parameters. To reduce the computational cost of the McMC and sensitivity indices, a cross-validated proxy model (i.e., Multivariate Adaptive Regression Spline) is constructed. The effect of different variants of differential evolution algorithm on the geological well test matching is also discussed. This paper provides a workflow for quantitative integration of well test data into the reservoir characterization workflow.

Challenges to be overcome using population-based sampling methods to recruit veterans for a study of post-traumatic stress disorder and traumatic brain injury

BackgroundMany investigators are interested in recruiting veterans from recent conflicts in Afghanistan and Iraq with Traumatic Brain Injury (TBI) and/or Post Traumatic Stress Disorder (PTSD). Researchers pursuing such studies may experience problems in recruiting sufficient numbers unless effective strategies are used. Currently, there is very little information on recruitment strategies for individuals with TBI and/or PTSD. It is known that groups of patients with medical conditions may be less likely to volunteer for clinical research. This study investigated the feasibility of recruiting veterans returning from recent military conflicts— Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) - using a population-based sampling method.MethodsIndividuals were sampled from a previous epidemiological study. Three study sites focused on recruiting survey respondents (n = 445) who lived within a 60 mile radius of one of the sites.ResultsOverall, the successful recruitment of veterans using a population-based sampling method was dependent on the ability to contact potential participants following mass mailing. Study enrollment of participants with probable TBI and/or PTSD had a recruitment yield (enrolled/total identified) of 5.4%. We were able to contact 146 individuals, representing a contact rate of 33%. Sixty-six of the individuals contacted were screened. The major reasons for not screening included a stated lack of interest in the study (n = 37), a failure to answer screening calls after initial contact (n = 30), and an unwillingness or inability to travel to a study site (n = 10). Based on the phone screening, 36 veterans were eligible for the study. Twenty-four veterans were enrolled, (recruitment yield = 5.4%) and twelve were not enrolled for a variety of reasons.ConclusionsOur experience with a population-based sampling method for recruitment of recent combat veterans illustrates the challenges encountered, particularly contacting and screening potential participants. The screening and enrollment data will help guide recruitment for future studies using population-based methods.

Letter to the Editor

Letter to the Editor

Antibiotic consumption and chlamydia prevalence in international studies

To determine whether there is an ecological association between antibiotic use and chlamydia prevalence. A systematic review was undertaken of international studies on chlamydia prevalence among women aged 15-25 years published between 2000 and 2005. Preference was given to studies using nucleic acid testing and representative population-based sampling methods. Data were obtained on per capita antibiotic consumption according to the defined daily dose. For the 12 countries for which both antibiotic consumption and relevant prevalence data for chlamydia were available, a non-significant negative correlation was found between total antibiotic consumption per capita and chlamydia prevalence among younger women according to country (r(s) = -0.242, P = 0.449). When an outlier (from the Netherlands) was excluded, the correlation was significant (r(s) = -0.615, P = 0.044). Combined use of tetracyclines and macrolides was also associated with lower chlamydia prevalence (r(s) = -0.697, P = 0.017). It is possible that antibiotics used for other reasons may have unexpectedly reduced the prevalence of chlamydia.