China
Africa
Explore chapters and articles related to this topic
Selected Issues in the Evaluation of Prenatal Care *
Published in Michele Kiely, Reproductive and Perinatal Epidemiology, 2019
Penny Liberatos, John L. Kiely
A summary of five studies21,44-47 examining the overall impact of prenatal care on reproductive outcome is presented in Table 1. In all five cases, the investigators reported significant negative relationships between the amount of prenatal care and the frequency of adverse pregnancy outcomes. Most of these studies attempted to deal with the problem of self-selection bias by statistically controlling for various demographic characteristics (usually those found on birth certificates). The confounding effect of length of gestation was sometimes controlled by adjusting for birthweight (when the outcome was mortality) or by using length of gestation itself as a control variable.
Evaluating Samples when Researchers Generalize
Published in Fred Pyrczak, Maria Tcherni-Buzzeo, Evaluating Research in Academic Journals, 2018
Fred Pyrczak, Maria Tcherni-Buzzeo
It is also important to consider what is called attrition, or selective dropout of participants from the study,18 for those studies that are conducted over a period of time (such studies are called longitudinal if done over longer periods of time19). If out of 120 participants who signed up for the study and completed the first round of interviews, only 70 are left by the third round of interviews one year later, it is important to compare the characteristics of those who dropped out of the study with those who stayed. If the two groups differ on some important study variables or demographic characteristics, the possibility of self-selection bias should be discussed by the researchers. It is very likely that by the third wave, the remaining participants are not as representative of the larger population as were the original 120, and thus the study results could be misleading or hard to generalize.
Causality in the Associations Between Exercise, Personality, and Mental Health
Published in Henning Budde, Mirko Wegner, The Exercise Effect on Mental Health, 2018
The above leads us to suggest that methodological difficulties in training studies in clinical samples with positive findings may have led us to overestimate the causal effects of exercise on mental health. However, there is also good ground for the opposite concern that training studies may actually act to underestimate the beneficial effects of exercise, particularly in the population at large. First of all, training studies tend to be relatively short, with a duration of the exercise activities of weeks or months at best. This will not capture effects of regular exercise that require more prolonged exposure and habit formation. Second, whereas training studies in patient samples may suffer from a self-selection bias, training studies in population-based samples will suffer from another form of selection bias related to inclusion or exclusion criteria set by researchers.
Biopsychosocial Model of Traumatic Stress Symptoms in Women Experiencing Homelessness: A Qualitative Descriptive Study
Published in Issues in Mental Health Nursing, 2023
Kirsten A. Dickins, Monique Reed, Olimpia Paun, Barbara Swanson, Niranjan S. Karnik
Self-selection bias may have limited the experiences and perspectives represented by the study sample. To address this limitation, we utilized targeted stratified recruitment to engage varied participant types who were representative of diverse sociodemographic and disciplinary backgrounds. Additionally, participant responses may have been influenced by social desirability bias. To reduce this threat, we assured participants of privacy and confidentiality and attempted to neutrally probe responses to all interview questions. Lastly, results may be unique to the contexts and timeframe during which data were collected. To mitigate this limitation, we recruited MHPs/staff from varied homeless shelter organization contexts, advertising the study to over 45 service provider organizations. While we worked in partnership with one homeless shelter to recruit WEH, recruitment occurred at two separate sites (overnight shelter, drop-in center) that served diverse clientele with differing needs; recruitment spanned from summer through fall to account for potential shifts in shelter service utilization by season. Lastly, while we attempted to ensure consistency and agreement in the interpretation/coding of data, such methods are limited in the context of qualitative analysis. Though inter-coder reliability was high, indicating consistent interpretation, interpretation may have been inaccurate. Further, qualitative analysis is distinct and different from positivist, objective discovery; utilizing a Kappa statistic may undermine the full allowance of an interpretivist viewpoint (MacDonald, Schoenebeck, & Forte, 2019).
Hypnotizability Norms may not be Representative of the General Population: Potential Sample and Self-Selection Bias Considerations
Published in International Journal of Clinical and Experimental Hypnosis, 2022
Burkhard Peter, R. Lynae Roberts
It should be considered that sample- and self-selection bias may interact with each other. For example, it is unknown to what extent the self-selection bias does apply to student samples, given that students can be “coerced” (Goss & Morosko, 1968, p. 237) or strongly encouraged by their professors to participate. In such cases, one should know whether the students had an a priori option to choose a professor whose hypnosis research interest was known to them. As another example, it is safe to assume that the 7,853 outpatients of Herbert Spiegel and the 735 of DeBetz were highly self-selected and do not represent the population of general practicing psychotherapists. Ultimately, the total degree of self- and sample-selection biases is unknown because of a lack of relevant data.
Beliefs About One’s Non-Suicidal Self-Injury: The Experiences of Self-Injury Questionnaire (ESIQ)
Published in Archives of Suicide Research, 2021
Devon B. Sandel, Khowla Jomar, Sheri L. Johnson, Joanne M. Dickson, Shannon Dandy, Rebecca Forrester, Peter J. Taylor
Several limitations must be acknowledged. Despite our attempts to consider generalizability, self-selection bias is likely as participants responded to advertisements. Although we have raised the idea that beliefs may shape the severity of NSSI, a more chronic or severe course of NSSI may lead to stronger positive beliefs about NSSI; longitudinal research is needed. ESIQ items were adapted from an initial pool of 50 P-CAN items which were adjusted to better fit with NSSI, revised, and new items were added. Nonetheless, by drawing on an existing measure we may have missed important facets of cognitions and experiences relevant to self-harm. The ESIQ items refer to “self-harm” due to the common use of this term among laypersons. In two samples (2 & 4) NSSI was explicitly defined as involving intentional non-suicidal behavior, and in two samples (1 & 3), this definition was not explicit. Despite differences in instructions, our findings generalized across samples. Future research could investigate how suicidal behavior shapes cognitions regarding self-injury.