Latent classification model for censored longitudinal binary outcome.

Latent classification model is a class of statistical methods for identifying unobserved class membership among the study samples using some observed data. In this study, we proposed a latent classification model that takes a censored longitudinal binary outcome variable and uses its changing pattern over time to predict individuals' latent class membership. Assuming the time-dependent outcome variables follow a continuous-time Markov chain, the proposed method has two primary goals: (1) estimate the distribution of the latent classes and predict individuals' class membership, and (2) estimate the class-specific transition rates and rate ratios. To assess the model's performance, we conducted a simulation study and verified that our algorithm produces accurate model estimates (ie, small bias) with reasonable confidence intervals (ie, achieving approximately 95% coverage probability). Furthermore, we compared our model to four other existing latent class models and demonstrated that our approach yields higher prediction accuracies for latent classes. We applied our proposed method to analyze the COVID-19 data in Houston, Texas, US collected between January first 2021 and December 31st 2021. Early reports on the COVID-19 pandemic showed that the severity of a SARS-CoV-2 infection tends to vary greatly by cases. We found that while demographic characteristics explain some of the differences in individuals' experience with COVID-19, some unaccounted-for latent variables were associated with the disease.

A Directed Content Analysis for Greatest Problems Among People With and Without Traumatic Brain Injury.

OBJECTIVE: To characterize the greatest problem or need among individuals with a history of traumatic brain injury (TBI), as compared with individuals with a history of other neurologic conditions, mental health conditions, and no history of neurologic or mental health conditions. DESIGN: A directed content analysis of open-text responses to a single online survey question using a framework guided by the Mayo-Portland Adaptability Inventory-4. SETTING: Community. PARTICIPANTS: A total of 2861 community-dwelling adults (n=274 with TBI; n=289 with other neurologic conditions besides TBI; n=454 with mental health conditions but no neurologic conditions; and n=1844 controls). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Open-text responses to the survey prompt: "What was your greatest problem or need over the past 2 weeks?" RESULTS: The Participation index comprised the greatest proportion of responses across all 4 participant groups. A quarter (25.4%) of controls reported None (no problem/need), whereas only 7.9%-10.7% of participants in all other groups reported None. Among all groups, individuals with TBI reported the greatest proportion of problems in the Adjustment and Ability indices. Among people with TBI, Money Management (19.7%), None (10.6%), and Anxiety (7.7%) were the 3 most frequently reported problems. Compared with individuals with mild TBI (mTBI), individuals with moderate-to-severe TBI (msTBI) reported a higher proportion of problems in the Ability and Adjustment indices. Among individuals with msTBI, the Adjustment index accounted for the greatest proportion of problems. CONCLUSIONS: This study employed a person-centered approach to understanding the greatest needs among individuals with TBI. Qualitative differences were observed between individuals with and without TBI, between people with mTBI and msTBI, and across genders among people with TBI. These findings can help guide research and policy toward addressing challenges perceived as highly important by people living in the community with TBI.

Mood Tracker: A Randomized Controlled Trial of a Self-Monitoring Intervention for Emotional Distress After Traumatic Brain Injury.

OBJECTIVE: Persons with traumatic brain injury (TBI) frequently experience emotional distress (ED) manifested in anxiety and depression. However, they may not access mental health services due to external (eg, access, transportation, and cost) or internal (eg, stigma and discomfort with traditional counseling) barriers. Based on substantial literature indicating that self-monitoring can ameliorate several health conditions, we conducted a randomized, parallel group, wait-list control (WLC) trial of a self-monitoring intervention to decrease ED after TBI. SETTING: Community in the southwestern United States. PARTICIPANTS: Persons with medically documented complicated mild, moderate, and severe TBI. DESIGN: About 127 participants were randomized in blocks of 6 to an active treatment (AT) group, wherein they completed multiple assessments of ED each week over a 6-week period via a smartphone app, or a WLC group in a parallel group, controlled trial. Participants received weekly support calls to promote self-monitoring of ED using ecological momentary assessment. MAIN MEASURES: ED (Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7), Satisfaction with Life Scale, and Participation Assessment with Recombined Tools-Objective. RESULTS: Analysis of the primary study outcome at 6 weeks after initiation of treatment for the AT group did not demonstrate that self-monitoring was effective in decreasing ED as compared to the WLC group. Brief support calls made weekly to promote compliance with self-monitoring were effective in achieving the target number of self-assessments. About 80% of support calls lasted less than 5 minutes. Greater ED was associated with lower life satisfaction and lower participation indicating the importance of addressing ED in persons with TBI. CONCLUSION: Additional work is needed to develop nontraditional interventions to circumvent barriers that prevent persons with TBI from accessing care for ED. Brief support calls may be an effective, low-cost intervention to improve compliance with self-monitoring or self-management interventions.

Characterizing Health Literacy and Its Correlates Among Individuals With Traumatic Brain Injury (TBI): A TBI Model Systems Study.

OBJECTIVE: To characterize health literacy among individuals with traumatic brain injury (TBI) at least a year postinjury and to explore its relationship to sociodemographic variables, injury severity, and cognition. SETTING: Community following discharge from inpatient rehabilitation. PARTICIPANTS: In total, 205 individuals with complicated mild to severe TBI who completed follow-up as part of a national longitudinal study of TBI and completed a web-based health literacy measure. DESIGN: Multicenter, cross-sectional, observational study. MAIN MEASURES: Health Literacy Assessment Using Talking Touchscreen Technology. RESULTS: Thirty-one percent of the sample demonstrated marginal/inadequate health literacy; 69% demonstrated adequate health literacy. A higher proportion of non-Hispanic White adults had adequate health literacy than non-Hispanic Black and Hispanic adults. Individuals with greater than a high school education were more likely to have adequate health literacy than those with a high school education or less. Better executive functioning performance was related to adequate health literacy. Better episodic memory performance was related to adequate health literacy, but only for those with complicated mild to moderate injury. CONCLUSIONS: A substantial proportion of individuals with TBI have marginal/inadequate health literacy, which may impact their understanding, appreciation, and use of health-related information and recommendations. While low health literacy may be preexisting, directly related to TBI, or a combination of both, it should be screened and considered by professionals when communicating with persons with TBI. Healthcare providers should tailor their communication approaches and presentation of health information, particularly for those with low health literacy.

The Relationship of Health Literacy to Health Outcomes Among Individuals With Traumatic Brain Injury: A Traumatic Brain Injury Model Systems Study.

OBJECTIVE: To examine the associations between health literacy and health outcomes among individuals with traumatic brain injury (TBI) at least a year post-injury. SETTING: Community following discharge from inpatient rehabilitation. PARTICIPANTS: A total of 205 individuals with complicated mild to severe TBI who completed a TBI Model Systems National Database follow-up interview and a web-based health literacy measure. DESIGN: A multicenter, cross-sectional, observational study. MAIN MEASURES: The Health Literacy Assessment Using Talking Touchscreen Technology (Health LiTT), number of comorbid conditions (Medical and Mental Health Comorbidities Interview [MMHCI]), perceived physical and mental health (PROMIS Global Physical and Mental Health subscales), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7). RESULTS: After controlling for sociodemographic, injury, cognition, and time post-injury, adequate health literacy was associated with higher odds of greater perceived physical health compared with participants with marginal/inadequate health literacy (odds ratio = 4.10; CI = 1.52-11.70]. Participants with inadequate/marginal health literacy had 3.50 times greater odds of depression (PHQ-9 ≥ 10) compared with those with adequate health literacy. Participants 45 years and older reported a greater number of MMHCI physical health conditions, but fewer MMHCI mental health conditions and GAD-7 anxiety symptoms compared with those who were younger. Non-Hispanic White participants and those with mild/moderate TBI were more likely to report a greater number of MMHCI mental health conditions compared with non-Hispanic Black participants or those with severe TBI. Greater time post-injury was associated with greater number of chronic physical and mental health conditions, and less odds of good-to-excellent perceived global mental health. CONCLUSIONS: Inadequate health literacy is associated with worse perceived physical health and greater depressive symptoms among adults with TBI. Greater efforts are needed to explore the mechanisms by which health literacy influences chronic disease management and mental health after TBI to improve postinjury health status and outcomes, particularly among those with limited health literacy skills.

Feasibility and user-experience of a virtual environment for social connection and education after stroke: A pilot study.

OBJECTIVES: To evaluate the feasibility and usability of stroke survivor participation in an 8-week virtual environment intervention that provides opportunities for social support exchanges, social network interactions, and recovery education. MATERIALS AND METHODS: A single-group, pre- and post-test measure design was used. Descriptive statistics were used to examine enrollment and retention rates, proportion of questionnaires completed, and virtual environment process data (e.g., number of log-ins) and usability scores. Changes in pre- and post-intervention questionnaire (e.g., usability, social support, depression, anxiety, loneliness, and self-efficacy) scores were explored using Wilcoxon signed-rank tests and paired t-test. RESULTS: Fifteen (65 %) of the eligible stroke survivors enrolled (60 % white, 27 % black), 12 (80 %) had an ischemic stroke, ages ranged from 33 to 74 years (mean 44 years), and mean months since stroke was 33 ± 23. Retention and questionnaire completion rates were both 93 % (n = 14). Survivors logged into the virtual environment a total of 122 times, logged an average of 49 min/log-in, and 12 (80 %) attended support groups and social activities. Median usability score indicated lower than average usability. Improvement trends in social support, loneliness, and depressive symptoms were found, but significant changes in mean questionnaire scores were not found. CONCLUSIONS: Overall, the results suggest that using a virtual environment to foster social support exchanges, social network interactions, and recovery education after stroke is feasible. Similar to other chronic disease populations, stroke survivor adoption of a virtual environment likely requires ongoing technical assistance, repetition of instructions, and opportunities for practice to reinforce engagement. TRIAL REGISTRATION: NCT05487144.

Incidence and Predictors of Breakthrough and Severe Breakthrough Infections of SARS-CoV-2 After Primary Series Vaccination in Adults: A Population-Based Survey of 22 575 Participants.

BACKGROUND: Breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are well documented. The current study estimates breakthrough incidence across pandemic waves, and evaluates predictors of breakthrough and severe breakthrough infections (defined as those requiring hospitalization). METHODS: In total, 89 762 participants underwent longitudinal antibody surveillance. Incidence rates were calculated using total person-days contributed. Bias-corrected and age-adjusted logistic regression determined multivariable predictors of breakthrough and severe breakthrough infection, respectively. RESULTS: The incidence was 0.45 (95% confidence interval [CI], .38-.50) during pre-Delta, 2.80 (95% CI, 2.25-3.14) during Delta, and 11.2 (95% CI, 8.80-12.95) during Omicron, per 10 000 person-days. Factors associated with elevated odds of breakthrough included Hispanic ethnicity (vs non-Hispanic white, OR = 1.243; 95% CI, 1.073-1.441), larger household size (OR = 1.251 [95% CI, 1.048-1.494] for 3-5 vs 1 and OR = 1.726 [95% CI, 1.317-2.262] for more than 5 vs 1 person), rural versus urban living (OR = 1.383; 95% CI, 1.122-1.704), receiving Pfizer or Johnson & Johnson versus Moderna, and multiple comorbidities. Of the 1700 breakthrough infections, 1665 reported on severity; 112 (6.73%) were severe. Higher body mass index, Hispanic ethnicity, vaccine type, asthma, and hypertension predicted severe breakthroughs. CONCLUSIONS: Breakthrough infection was 4-25 times more common during the Omicron-dominant wave versus earlier waves. Higher burden of severe breakthrough infections was identified in subgroups.

Antibody Duration After Infection From SARS-CoV-2 in the Texas Coronavirus Antibody Response Survey.

Understanding the duration of antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that causes COVID-19 is important to controlling the current pandemic. Participants from the Texas Coronavirus Antibody Response Survey (Texas CARES) with at least 1 nucleocapsid protein antibody test were selected for a longitudinal analysis of antibody duration. A linear mixed model was fit to data from participants (n = 4553) with 1 to 3 antibody tests over 11 months (1 October 2020 to 16 September 2021), and models fit showed that expected antibody response after COVID-19 infection robustly increases for 100 days postinfection, and predicts individuals may remain antibody positive from natural infection beyond 500 days depending on age, body mass index, smoking or vaping use, and disease severity (hospitalized or not; symptomatic or not).

Estimation of non-monotonic transition rates in a semi-Markov process with covariates adjustments and application to caregivers' stress data.

With the large ongoing number of aged people and Alzheimer's disease (AD) patients worldwide, unpaid caregivers have become the primary sources of their daily caregiving. Alzheimer's family caregivers often suffer from physical and mental morbidities owing to various reasons. The aims of this paper were to develop alternate methods to understand the transition properties, the dynamic change, and the long-run behavior of AD caregivers' stress levels, by assuming their transition to the next level only depends on the duration of the current stress level. In this paper, we modeled the transition rates in the semi-Markov Process with log-logistic hazard functions. We assumed the transition rates were non-monotonic over time and the scale of transition rates depended on covariates. We also extended the uniform accelerated expansion to calculate the long-run probability distribution of stress levels while adjusting for multiple covariates. The proposed methods were evaluated through an empirical study. The application results showed that all the transition rates of caregivers' stress levels were right skewed. Care recipients' baseline age was significantly associated with the transitions. The long-run probability of severe state was slightly higher, implying a prolonged recovery time for severe stress patients.

Coping With Chronic Pain After Traumatic Brain Injury: Role of Race/Ethnicity and Effect on Participation Outcomes in a TBI Model Systems Sample.

OBJECTIVE: To investigate catastrophizing and self-efficacy for managing pain among Non-Hispanic Whites, Non-Hispanic Blacks, and Hispanics with chronic pain after traumatic brain injury (TBI), and whether coping interacts with race/ethnicity to predict participation outcomes. SETTING: Community after discharge from inpatient rehabilitation. PARTICIPANTS: 621 individuals with moderate to severe TBI and chronic pain, who completed follow-up as part of a national longitudinal study of TBI and also participated in a collaborative study on chronic pain. DESIGN: Multicenter, cross-sectional, survey study. MAIN MEASURES: Catastrophizing subscale from the Coping With Pain Scale; Pain Self-Efficacy Questionnaire; Participation Assessment With Recombined Tools-Objective. RESULTS: After controlling for relevant sociodemographic variables, a significant interaction was observed between race/ethnicity and insurance status, such that Blacks who had public health insurance reported greater catastrophizing in response to pain compared with Whites. Race/ethnicity and self-efficacy for managing pain were unrelated. Greater catastrophizing was associated with lower participation but did not interact with race/ethnicity. Blacks reported lower participation relative to Whites, independent of catastrophizing. CONCLUSIONS: Black individuals who have TBI and chronic pain, and who have public insurance, may be vulnerable to difficulties managing pain. They are more likely to cope by catastrophizing, and catastrophizing is related to worse participation outcomes. The results suggest that access to care may affect response to chronic pain after TBI.

Disparities in Chronic Pain Experience and Treatment History Among Persons With Traumatic Brain Injury: A Traumatic Brain Injury Model Systems Study.

OBJECTIVE: To determine disparities in pain severity, pain interference, and history of pain treatment for non-Hispanic Whites, non-Hispanic Blacks, and Hispanics with traumatic brain injury (TBI) and chronic pain. SETTING: Community following discharge from inpatient rehabilitation. PARTICIPANTS: A total of 621 individuals with medically documented moderate to severe TBI who had received acute trauma care and inpatient rehabilitation (440 non-Hispanic Whites, 111 non-Hispanic Blacks, and 70 Hispanics). DESIGN: A multicenter, cross-sectional, survey study. MAIN MEASURES: Brief Pain Inventory; receipt of opioid prescription; receipt of nonpharmacologic pain treatments; and receipt of comprehensive interdisciplinary pain rehabilitation. RESULTS: After controlling for relevant sociodemographic variables, non-Hispanic Blacks reported greater pain severity and greater pain interference relative to non-Hispanic Whites. Race/ethnicity interacted with age, such that the differences between Whites and Blacks were greater for older participants (for severity and interference) and for those with less than a high school education (for interference). There were no differences found between the racial/ethnic groups in the odds of having ever received pain treatment. CONCLUSIONS: Among individuals with TBI who report chronic pain, non-Hispanic Blacks may be more vulnerable to difficulties managing pain severity and to interference of pain in activities and mood. Systemic biases experienced by many Black individuals with regard to social determinants of health must be considered in a holistic approach to assessing and treating chronic pain in individuals with TBI.

Evaluating the impact of using a wound-specific oral nutritional supplement to support wound healing in a rehabilitation setting.

Chronic wounds adversely affect patient quality of life, increase the risk of mortality, and impose high costs on healthcare systems. Since protein-energy malnutrition or specific nutrient deficiencies can delay wound healing, nutritionally focused care is a key strategy to help prevent or treat the occurrence of non-healing wounds. The objective of our study of inpatients in a rehabilitation hospital was to quantify the effect of daily wound-specific oral nutritional supplementation (WS-ONS) on healing chronic wounds. Using electronic medical records, we conducted a retrospective analysis of patients with chronic wounds. We identified records for (a) a treatment group who received standard wound care + usual hospital diet + daily WS-ONS for ≥14 days, and (b) a control group who received standard wound care + a usual hospital diet. We collected data for demographics, nutritional status, and wound-relevant health characteristics. We examined weekly measurements of wound number and sizes (surface area for superficial wounds or volume for non-superficial wounds). There were 341 patients identified, 114 with 322 wounds in the treatment group and 227 patients with 420 wounds in the control group. We found that rehabilitation inpatients who were given nutritional support had larger wounds and lower functional independence on admission. At discharge, wound area reduction (percent) was nearly two-fold better in patients who were given daily WS-ONS + usual hospital diet compared to those who consumed usual diet only (61.1% vs 34.5%). Overall, weekly wound improvement (lowered wound area or wound volume) was more likely in the WS-ONS group than in the Control group, particularly from the start of care to week 2. Inpatients with largest wounds and lowest functional independence on admission were most likely to be given WS-ONS, an indication that caregivers recognised the need for supplementation. Week-to-week improvement in wound size was more likely in patients who received WS-ONS than in those who did not. Specifically, wound areas and wound volumes were significantly lower at discharge among patients who were given specialised nutritional support. More research in this field is needed to improve care and reduce healthcare costs.

External validation of a model determining risk of neoplastic progression of Barrett's esophagus in a cohort of U.S. veterans.

BACKGROUND AND AIMS: Risk of esophageal adenocarcinoma (EAC) in those with Barrett's esophagus (BE) is 11-fold greater than the general population. It remains unclear which BE patients are at highest risk of progression to EAC. We aimed to validate a predictive model risk-stratifying BE patients. METHODS: We conducted a retrospective cohort study at the Houston Veteran Affairs Medical Center of consecutive patients with a new diagnosis of BE from November 1990 to January 2019. Study follow-up was through February 2020. Patients were excluded if they had no follow-up EGD with esophageal biopsy sampling after the initial BE-diagnosing EGD or evidence of high-grade dysplasia (HGD) or EAC on initial EGD. We performed an external validation study of a risk model containing sex, smoking, BE length, and low-grade dysplasia (LGD) status and assessed discriminatory ability using the area under the receiver operating characteristic curve (AUROC). RESULTS: Among 608 BE patients, 24 progressed to HGD/EAC. The points-based model discriminated well with an AUROC of .72 (95% confidence interval [CI], .63-.82). When categorized into low-, intermediate-, and high-risk groups according to published cutoffs, the AUROC was poor at .57. Restructured into low-risk versus high-risk groups, the AUROC was .72 (95% CI, .64-.80). Excluding baseline LGD did not reduce discriminatory ability (AUROC, .73; 95% CI, .64-.82). CONCLUSIONS: This external validation provides further evidence that the model including sex, LGD status, smoking status, and BE length may help to risk stratify BE patients. A simplified version excluding LGD status and/or reducing the number of risk groups has increased utility in clinical practice without loss of discriminatory ability.

Relationships of self-awareness and facial affect recognition to social communication ability in persons with traumatic brain injury.

Traumatic brain injury (TBI) can cause changes to the injured person's physical ability, cognitive functioning, and social interactions. Since these attributes largely determine a person's concept of who they are, TBI poses a threat to sense of self. Due to the importance of social communication skills for community integration, impairment of these skills is a particular threat to sense of self. The present investigation sought to explore characteristics that influence social communication abilities. We hypothesized that both ability to interpret facial affect and self-awareness would be associated with communication ability. We also expected that facial affect recognition would influence self-awareness and that the effect of facial affect recognition on social communication would be partially mediated by self-awareness. For this prospective cohort study, participants were 77 individuals with documented TBI. Of these, 65% were male and 83% sustained severe injuries. The hypothesized association of facial affect recognition with social communication was demonstrated with path analysis as was the effect of facial affect recognition on self-awareness. However, the effect of facial affect recognition on social communication was not mediated by self-awareness. In addition, social communication was associated with employment, social integration, and loneliness. Findings highlighted the importance of social communication after TBI.

Understanding loss to follow-up in a longitudinal study of people with traumatic brain injury.

OBJECTIVE: To examine factors related to attrition in a traumatic brain injury (TBI) study sample assessed up to 15 years after injury. PARTICIPANTS: One thousand twenty-eight participants with TBI who completed the year 1 follow-up assessment at a TBI Model Systems Center between 1992 and 2018. METHOD: Secondary analysis of data from a prospective longitudinal cohort study considering follow-up data collection completion status at years 1, 2, 5, 10, and 15. RESULTS: In univariable analyses, multiple factors were associated with loss to follow-up (LOFU) including being a member of a socially disadvantaged group, substance use history, residence, payor, cause of injury, and results of earlier follow-up attempts. In a multiple logistic regression analysis examining the prediction of follow-up condition at 10 or 15 years post-injury, only payor and race/ethnicity were significant predictors. Hispanic ethnicity was associated with higher odds of LOFU, and these participants often spoke Spanish and were born outside of the United States. CONCLUSIONS: The findings suggest a need to understand sociodemographic variables and their influence on participant attrition in longitudinal TBI research. With a better understanding of these predictors, procedures can be developed to address retention of participants who are identified as being at increased risk for study drop out.

A randomized controlled trial of acceptance and commitment therapy for psychological distress among persons with traumatic brain injury.

Psychological distress is common in persons with traumatic brain injury (TBI) but treatments remain underdeveloped. This randomized controlled trial of Acceptance and Commitment Therapy (ACT) was designed to address this gap. Ninety-three persons with medically-documented complicated mild to severe TBI, normal-to-mildly impaired memory, and clinically significant psychological distress in the chronic phase of recovery were randomized to receive eight weeks of ACT (manualized with adaptations to address TBI-related cognitive impairments) or a single session of needs assessment, brief counseling/education, and referral. The ACT group showed significantly greater reduction of psychological distress (Brief Symptom Inventory 18) and demonstrated improvements in psychological flexibility and commitment to action (Acceptance and Action Questionnaire-II (AAQ-II) scores). The number of treatment responders (post-treatment BSI 18 GSI T scores <63) was larger in the ACT group than in the control group. Entry of AAQ-II scores into the model of between-group differences in BSI 18 GSI T scores indicated that core ACT processes explained the variance in treatment group outcomes. Provision of ACT reduces psychological distress in persons with TBI in the chronic phase of recovery when adaptations are made to accommodate TBI-related cognitive impairments. Additional clinical trials with a structurally equivalent control group are needed.

Time trends and predictors of survival in surgically resected early-stage non-small cell lung cancer patients.

BACKGROUND: The improvement in the management of lung cancer have the potential to improve survival in patients undergoing resection for early-stage (stage I and II) non-small cell lung cancer (NSCLC), but few studies have evaluated time trends and identified predictors of overall survival (OS). METHODS: We identified surgically resected early-stage NSCLC between 1998 and 2016. The 3-year OS (1998-2014) and 5-year OS (1998-2012) rates were calculated for each year. Joinpoint regression was used to calculate annual percentage changes (APC) and to test time trends in OS. Multivariable Cox regression was used to identify predictors of OS. RESULTS: There was a significant upward trend in the 3-year (1998, 56%; 2014, 83%; APC = 1.8) and 5-year (1998, 47%; 2012, 76%; APC = 3.1) OS. Older age; male sex; history of diabetes, coronary artery disease, and chronic obstructive pulmonary disease; high ASA score; smoking pack-years; high-grade tumor; pneumonectomy; thoracotomy; neoadjuvant therapy; nodal disease; and positive tumor margin were predictors of poor OS. CONCLUSION: The upward time trend in OS suggests that improved staging, patient selection, and management have conferred a survival benefit in early-stage NSCLC patients. The prediction model of OS could be used to refine selection criteria for resection and improve survival outcomes.

Patterns of Cognitive Test Scores and Symptom Complaints in Persons with TBI Who Failed Performance Validity Testing.

OBJECTIVE: To determine clinically meaningful subgroups of persons with traumatic brain injury (TBI) who have failed performance validity testing. METHOD: Study participants were selected from a cohort of 674 participants with definitive medical evidence of TBI. Participants were those who failed performance validity testing (the Word Memory Test, using the standard cutoffs). Participants were administered cognitive tests and self-report questionnaires. Test and questionnaire results were summarized as 12 dimension scores. Cluster analysis using the k-means method was performed. RESULTS: Cluster analysis for the 143 retained participants indicated three subgroups. These subgroups differed on patterns of scores. Subgroup 1 was impaired for memory and had no excessive complaints. Subgroup 2 had impaired memory and processing speed as well as concern regarding cognition function. Subgroup 3 showed impairment on all cognitive tests and excess complaints in multiple areas. CONCLUSIONS: These results provide a preliminary basis for improved understanding of poor performance validity.

Conceptual Structure of Health-Related Quality of Life for Persons With Traumatic Brain Injury: Confirmatory Factor Analysis of the TBI-QOL.

OBJECTIVE: To determine the factor structure of the Traumatic Brain Injury-Quality of Life (TBI-QOL) measurement system. DESIGN: Observational. SETTING: 3 TBI Model Systems rehabilitation centers. PARTICIPANTS: Twenty TBI-QOL item banks were administered to a sample of community-dwelling adults with TBI (N=504) as part of a study of TBI classification. A subsample of participants (n=200) was randomly selected for exploratory factor analyses, while data from the remaining participants (n=304) were used for the confirmatory factor analysis. To examine a wide range of conceptual models, confirmatory factor analyses were conducted on a total of 16 models, ranging from 1 to 7 factors. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Not applicable. RESULTS: Initial exploratory factor analysis yielded support for a 5-factor model (negative emotion, cognitive impairment, functioning and participation, positive emotion, pain). Confirmatory factor analysis results, however, indicated a 7-factor model including physical function, physical symptoms, cognition, negative emotion, positive emotion, sense of self, and social participation (model 16; robust fit statistics root mean square error of approximation =.063, standardized root mean square residual =.035, comparative fit index =.955, Tucker-Lewis Index =.943, Bayes Information Criterion =40059.44). CONCLUSIONS: The complex 7-factor model of the TBI-QOL provides a more nuanced framework for understanding health-related quality of life for persons with TBI than the commonly used 3-factor model including physical health, mental health, and social health.

Responsiveness of the Traumatic Brain Injury-Quality of Life (TBI-QOL) Measurement System.

OBJECTIVE: To assess the responsiveness of the Traumatic Brain Injury-Quality of Life (TBI-QOL) measurement system. DESIGN: Participants completed the 20 TBI-QOL item banks and the Participation Assessment with Recombined Tools-Objective (PART-O) Productivity Subscale at baseline and 6-month follow-up assessments. Participants were categorized into 4 groups (increased productivity, unchanged productivity, and decreased productivity) based on PART-O Productivity scores. Paired sample t tests were used to compare TBI-QOL scores at baseline and 6 months, and standardized response means and Cohen's d were computed to estimate effect sizes. SETTING: Three traumatic brain injury (TBI) Model Systems rehabilitation centers in the United States. PARTICIPANTS: Two hundred one community-dwelling adults with TBI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: 20 TBI-QOL item banks. RESULTS: As expected, given that there was no intervention, group mean TBI-QOL subdomain scores for the entire sample showed no change or small improvement over the 6-month study period. At the follow-up assessment, 72 participants reported increased productivity, 71 reported decreased productivity, and 58 reported the same level of productivity as they had 6 months prior. When compared with participants who reported unchanged or decreased productivity, participants who reported increased productivity on the PART-O subscale had clinically meaningful (d≥0.30) improvements on 7 TBI-QOL measures. The largest improvement was in the Independence subdomain (mean change, 7.06; df=0.84), with differences also observed in the Mobility, Positive Affect and Well-Being, Resilience, Grief/Loss, Ability to Participate, and Satisfaction with Participation subdomains. CONCLUSIONS: The 20 TBI-QOL item banks demonstrate responsiveness to change and measurement stability in a community-dwelling sample. Researchers may use the TBI-QOL to detect changes in HRQOL after a clinical intervention and clinicians may use it in their daily practices to monitor patient recovery.