Nevin Manimala

Psychol Methods. 2021 Jul 29. doi: 10.1037/met0000314. Online ahead of print.

ABSTRACT

hen multiple mediators exist on the causal pathway from treatment to outcome, path analysis prevails for disentangling indirect effects along paths linking possibly several mediators. However, separately evaluating each indirect effect along different posited paths demands stringent assumptions, such as correctly specifying the mediators’ causal structure, and no unobserved confounding among the mediators. These assumptions may be unfalsifiable in practice and, when they fail to hold, can result in misleading conclusions about the mediators. Nevertheless, these assumptions are avoidable when substantive interest is in inference about the indirect effects specific to each distinct mediator. In this article, we introduce a new definition of indirect effects called interventional indirect effects from the causal inference and epidemiology literature. Interventional indirect effects can be unbiasedly estimated without the assumptions above while retaining scientifically meaningful interpretations. We show that under a typical class of linear and additive mean models, estimators of interventional indirect effects adopt the same analytical form as prevalent product-of-coefficient estimators assuming a parallel mediator model. Prevalent estimators are therefore unbiased when estimating interventional indirect effects-even when there are unknown causal effects among the mediators-but require a different causal interpretation. When other mediators moderate the effect of each mediator on the outcome, and the mediators’ covariance is affected by treatment, such an indirect effect due to the mediators’ mutual dependence (on one another) cannot be attributed to any mediator alone. We exploit the proposed definitions of interventional indirect effects to develop novel estimators under such settings. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323583 | DOI:10.1037/met0000314

J Exp Psychol Learn Mem Cogn. 2021 Jul 29. doi: 10.1037/xlm0000894. Online ahead of print.

ABSTRACT

Theories of memory consolidation suggest that initially rich, vivid memories become more gist-like over time. However, it is unclear whether gist-like representations reflect a loss of detail through degradation or the blending of experiences into statistical averages, and whether the strength of these representations increases, decreases, or remains stable over time. We report three behavioral experiments that address these questions by examining distributional learning during spatial navigation. In Experiment 1, human subjects navigated a virtual maze to find hidden objects with locations varying according to spatial distributions. After 15 minutes, 1 day, 7 days, or 28 days, we tested their navigation performance and explicit memory. In Experiment 2, we created spatial distributions with no object at their mean locations, thereby disentangling learned object exemplars from statistical averages. In Experiment 3, we created only a single, bimodal distribution to avoid possible confusion between distributions and administered tests after 15 minutes or 28 days. Across all experiments, and for both navigation and explicit tests, representations of the spatial distributions were present soon after exposure, but then receded over time. These findings suggest gist-like representations do not improve over time, helping to clarify the temporal dynamics of consolidation in human learning and memory. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323577 | DOI:10.1037/xlm0000894

Health Psychol. 2021 Jul 29. doi: 10.1037/hea0001071. Online ahead of print.

ABSTRACT

Objective: Interventions to promote evidence-based practices are particularly needed for paraprofessional staff working with minority youth with HIV who have higher rates of HIV infection but lower rates of linkage and retention in care compared to older adults. Utilizing the ORBIT model for behavioral intervention development, we defined and refined a behavioral intervention for providers, Tailored Motivational Interviewing (TMI), to improve provider competence in previous studies (Phase 1a and 1b). The current study focuses on ORBIT Phase 2a-proof of concept. We hypothesized that TMI would be acceptable and feasible and would show a signal of efficacy of improving and maintaining community health worker (CHW) MI competence scores using an innovative statistical method for small N proof-of-concept studies. Method: Longitudinal data were collected from 19 CHWs at 16 youth HIV agencies. CHWs from 8 sites were assigned to the TMI group per the cofunders request. The remaining 8 sites were randomly assigned to TMI or services as usual. MI competence was assessed at baseline and up to 15 times over 2 years. Random coefficient models were utilized to examine time trajectories of competence scores and the impact of the intervention on competence trajectories. Semistructured interviews were conducted to determine barriers and facilitators of TMI. Results: Competence scores in the TMI group significantly increased while the scores of the control group significantly decreased. Further analysis of the intervention group demonstrated that scores significantly increased during the first 3 months after initial workshop and was sustained through the end of the study. Qualitative findings revealed insufficient time and competing priorities as perceived barriers whereas integrating MI into routine agency practices and ongoing training might facilitate implementation. Conclusions: Following a successful proof-of-concept, the next step is a fully randomized pilot study of TMI relative to a control condition in preparation for a stepped-wedge cluster randomized full scale trial. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323574 | DOI:10.1037/hea0001071

Psychol Assess. 2021 Jul 29. doi: 10.1037/pas0001048. Online ahead of print.

ABSTRACT

It is often important to study people’s thoughts, feelings, and behaviors over time. To this end, researchers have relied on repeated cross-sectional (RCS) studies, in which different people from the same population participate on different measurement occasions. Also, researchers have relied on panel studies, in which the same group of people participate on different measurement occasions. However, few studies have directly tested whether participants’ responses in RCS studies were similar to those found in panel studies. To address this gap, we compared the responses to 33 items, 28 of which were further grouped into four aggregates (Affections, Worries, States, Health concerns), over 8 weeks during the first COVID-19 lockdown in Denmark in a RCS study (overall N = 5,993, per measurement occasion 616 ≤ n ≤ 964) with the responses in a largely equivalent panel study (993 ≤ n ≤ 2,546 across measurement occasions). The study participants were randomly drawn from the same quota-representative participant pool and responded to the same items on the same measurement occasions. Results indicated a few differences between the study samples on the first measurement occasion (i.e., selection effects between studies). Further, we found statistical support for different trajectories in 21 aggregates/items. However, visual inspection of the trajectories suggested subtle differences between the studies at large. The results thus raise awareness that the trajectories of people’s thoughts, feelings, and behaviors can differ between survey methods, especially when only a few measurement occasions are considered. Nevertheless, such differences might not be substantial over time. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323551 | DOI:10.1037/pas0001048

Health Psychol. 2021 Jun;40(6):408-417. doi: 10.1037/hea0001080.

ABSTRACT

OBJECTIVE: Uveal melanoma, a rare eye cancer, presents potential vision loss and life threat. This prospective, longitudinal study interrogated the predictive utility of visual impairment, as moderated by optimism/pessimism, on depressive symptoms in 299 adults undergoing diagnostic evaluation.

METHOD: Depressive symptoms (Center for Epidemiologic Studies Depression Scale), subjective (Measure of Outcome in Ocular Disease vision subscale) and objective (logarithm of the minimum angle of resolution) visual impairment, and optimism/pessimism (Life Orientation Test-Revised) were assessed before diagnostic evaluation and 1 week, 3 months, and 12 months after diagnosis. Multilevel modeling, with repeated measures (Level 1) nested within individuals (Level 2) and imputation of missing data (Blimp software), was performed.

RESULTS: Depressive symptoms were significantly more elevated 1 week after diagnosis in cancer patients (n = 107) versus patients not diagnosed with cancer (n = 192). Higher subjective (but not objective) visual impairment predicted greater depressive symptoms (p < .001). Across the entire sample, the two-way (Optimism/Pessimism × Subjective Visual Impairment) interactions were statistically significant (ps < .05), but not the three-way interaction (with diagnosis). The positive association between subjective visual impairment and depressive symptoms was significant at low and moderate levels of optimism (ps < .001), but not at high optimism (p > .05). The association was significant at high and moderate levels (ps < .001), but not low (p > .05) levels of pessimism.

CONCLUSIONS: Elevated depressive symptoms are evident in adults who do (vs. do not) receive a diagnosis of uveal melanoma but appear to remit within 3 months. Perceived impaired vision, especially coupled with low optimism or high pessimism, predicts depressive symptoms over time, with implications for intervention. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323543 | DOI:10.1037/hea0001080

J Exp Psychol Gen. 2021 Jul 29. doi: 10.1037/xge0001056. Online ahead of print.

ABSTRACT

The link between status and self-esteem remains theoretically and empirically controversial. To help clarify it, we proposed an integrated account of status and self-esteem, and tested several hypotheses derived from it. We distinguished between two types of status: socioeconomic status (SES; education, income, occupation) and sociometric status (SMS; respect, admiration, importance). We then examined how they related to one another and to self-esteem across five studies (N = 2,018). As hypothesized, in Studies 1-2 (cross-sectional), SES and SMS correlated positively with one another, and both correlated positively with self-esteem, yet SMS predicted self-esteem more strongly than SES did. Moreover, SMS mediated the link between SES and self-esteem, and this statistical model fit the data better than an alternative model where SMS and SES reversed roles. Studies 3-5 demonstrated causal links experimentally. In Study 3, manipulating SES to be higher (vs. lower) led to higher (vs. lower) SMS and state self-esteem, with SMS again statistically mediating the impact of SES on state self-esteem. In Study 4, manipulating SMS to be higher (vs. lower) led to higher (vs. lower) state self-esteem. Finally, in Study 5, manipulating SMS showed that it causally mediated the link between SES and state self-esteem. Our findings persisted across multiple measurement formats and after controlling for the Big Five personality traits. They point to SMS being a more powerful and proximate predictor of self-esteem than SES, thereby illuminating the link between status and self-esteem, and adding to a growing literature on the psychology of status. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

PMID:34323535 | DOI:10.1037/xge0001056

Pain Physician. 2021 Aug;24(5):E649-E660.

ABSTRACT

BACKGROUND: Plasma rich in growth factors (PRGF) is a leukocyte-free platelet-rich plasma (PRP) that is an effective biological approach to tissue repair and has been demonstrated to significantly improve multiple conditions, including low back pain and degenerative disc pathology.

OBJECTIVES: The objective of this retrospective study was to analyze the effectiveness of treating both cervical and lumbar spine pain with minimally invasive infiltrations of PRGF-Endoret.

STUDY DESIGN: Retrospective study design.

SETTING: Outpatient private practice facility.

METHODS: The effectiveness of PRGF has been assessed by patient-reported outcomes (PRO) through validated questionnaires, namely Numeric Rating Scale (NRS) for back pain, Spine Tango Core Outcome Measure Index (COMI) Questionnaire for lumbar and cervical pain, and OSWESTRY Disability Index questionnaire for lumbar pain cases. Score differences between pre- and post-treatment have also been assessed stratified for multiple sub-groups of patients based on the sector of the column treated, gender, and age.

RESULTS: This study includes 65 patients (18 with cervical pain and 47 with lumbar back pain). The average time of back pain evolution was 10 years. Patients received at least 2 PRGF infiltration series about one month apart. Each patient received intervertebral disc and epidural infiltrations, root infiltrations, in case of radicular injury, and intraarticular infiltrations, in case of osteoarthritis of the facet joints. Results show statistically significant (P < 0.05) improvements on all analyzed scores. Regarding the stratified analyses, 249 (99%) sub-groups showed an improvement in all tests (252 cases overall). From the 249 improving cases, 154 (62%) showed a statistically significant difference between the pre- and the post- treatment periods.

LIMITATIONS: This research is a retrospective study with a relatively small sample cohort. Only PRO have been assessed.

CONCLUSIONS: According to the results obtained in this study, and taking into account their limitations, PRGF infiltrations are an effective and minimally invasive biological strategy in the treatment of both cervical and lumbar pain, evaluated according to PRO.

PMID:34323453

Pain Physician. 2021 Aug;24(5):E611-E617.

ABSTRACT

BACKGROUND: We previously reported on a combined technique and initial data of hip denervation using an anterior approach and cooled radiofrequency.

OBJECTIVES: A large retrospective study to evaluate the long-term effectiveness of cooled radiofrequency ablation (CRFA) in the general chronic hip pain population.

STUDY DESIGN: Retrospective electronic chart review.

SETTING: A single specialty private practice.

METHODS: Retrospective chart review of 235 consecutive (CRFA) in 136 patients with chronic hip pain.

RESULTS: Out of 235 CRFA, 178 (96 initial procedures and 82 repeats) were performed in 84 patients with 12 or more months follow-up. The average decrease in visual analog scale (VAS) pain scores was 7.3 ± 1.3 to 2.3 ± 1.5 and 2.48 ± 1.5 for the first and second diagnostic block, respectively, and was statistically significant (P < 0.001). Similarly, the average decrease in VAS pain scores at 6 and 12 months after CRFA denervation was 3.44 ± 2.5 and 4.23 ± 2.5, respectively; P < 0.001. Out of the 96 initial procedures in 84 patients, 66 procedures (69%) provided more than 50% relief at 6 months, and 50 (52%) at 12 months. There were 82 repeat denervations in 36 patients. Repeated procedures in the same patients provided a similar degree of pain relief with no statistically significant difference in the median pain scores (2.8 ± 2.1 cm vs 3.1 ± 1.7 cm ; P = 0.197) or time interval of pain relief (12.7 ± 10.9 vs 10.3 ± 4.7; P = 0.508). There were 3 minor complications.

LIMITATIONS: Retrospective nature of the study.

CONCLUSION: Improvements in pain scores and longevity of pain relief from chronic hip pain using a simple, anterior approach to radiofrequency denervation of the lateral obturator and lateral femoral nerves justifies further randomized prospective trials. Repeated CRFAs demonstrated consistency in pain relief and absolute safety of repeated denervation.

PMID:34323448

Pain Physician. 2021 Aug;24(5):E595-E600.

ABSTRACT

BACKGROUND: In order to clarify the camera image and open the adhesions mechanically during epiduroscopy, saline is injected continuously in the epidural area. As a result, an increase in intracranial pressure is to be expected in theory. Increased intracranial pressure can be evaluated by measuring by optic nerve sheath diameter.

OBJECTIVES: This study was designed to evaluate the relationship between optic nerve sheath diameter measurements and intracranial pressure, after injecting fluid to the epidural area during epiduroscopy procedures performed in our clinic.

STUDY DESIGN: Retrospective study.

SETTING: Sakarya University Training and Research Hospital.

METHODS: During the epiduroscopy procedure, pre and postoperative bilateral optic nerve sheath diameters were measured with an ultrasonography probe. With the patients’ eyelids closed, the probe was placed on the orbita in the sagittal plane, measuring 3 mm posterior of the papilla.

RESULTS: While there was a statistically significant difference between pre- and post-operative optic nerve sheath diameter measurements, there was no significant correlation with processing time, amount of fluid delivered, or fluid delivery rates.

LIMITATIONS: One of the limitations of this study is the retrospective collection of data. A second limitation is that repetitive measurements were not performed, instead of a single postoperative measurement.

CONCLUSION: We think more prospective randomized controlled studies are required to examine the increase in the diameter of the optic nerve sheath, which is an indirect indicator of increased intracranial pressure after epiduroscopy applications, in order to determine whether the pressure increase is associated with the rate of fluid delivery, the total fluid amount, or the processing time.

PMID:34323446

Pain Physician. 2021 Aug;24(5):E573-E581.

ABSTRACT

BACKGROUND: Mechanical compression on the trigeminal root entry zone (TREZ) by microvascular is the main etiology of primary trigeminal neuralgia (TN).

OBJECTIVES: To study the pathogenesis of TN, hub genes screening in the TREZ of TN in an animal model was performed.

STUDY DESIGN: A double blind, randomized study was designed in a controlled animal trial.

SETTING: The research took place in the Laboratory of Clinical Applied Anatomy at the School of Basic Medical Science of Fujian Medical University.

METHODS: Twelve male rats were randomly divided into a sham operation group and a TN animal model group. TN animal model was induced by chronic compression of trigeminal nerve root (CCT) operation. Gene expression in the TREZ were analyzed by RNA sequencing (RNA-Seq) technique. KEGG analysis, GO analysis, and PPI analysis were performed in the DEGs. Key signaling pathways analyzing by GSEA and the hub genes in the DEGs were also studied. Reverse transcription real-time polymerase chain reaction (RT-qPCR) was used to verify the RNA-Seq results.

RESULTS: Transcriptome data showed that 352 genes up-regulated and 59 genes down-regulated in DEGs on post-operation day 21, after CCT operation in the TN group. KEGG analysis revealed that, “neuroactive ligand receptor interaction” and “cytokine cytokine receptor interaction” may be related to the pathogenesis of TN. GO analysis showed “regulation of signing receptor activity”, “chemokine activity”, and “carbohydrate binging” may be related to TN. The RT-qPCR results were consistent with the test results, indicating that the transcriptome sequencing results were reliable.

LIMITATIONS: Although the incidence of TN in female rats was higher than in male rats, we only used male SD rats to establish the TN animal model, to avoid the effect of estrogen on experimental results. This study only presents some respects of RNA-Seq technique and, therefore, did not identify the DEGs at the protein level. The relationship between the DEGs at different levels shoud be done in the future.

CONCLUSIONS: Based on the results of RNA-seq, this study discovered 6 hub genes in the TREZ that are closely related to the TN animal model, which provide a potential breakthrough point to explore the pathogenesis of TN.

PMID:34323444