Identifiability and estimability of Bayesian linear and nonlinear crossed random effects models

Crossed random effects models (CREMs) are particularly useful in longitudinal data applications because they allow researchers to account for the impact of dynamic group membership on individual outcomes. However, no research has determined what data conditions need to be met to sufficiently identify these models, especially the group effects, in a longitudinal context. This is a significant gap in the current literature as future applications to real data may need to consider these conditions to yield accurate and precise model parameter estimates, specifically for the group effects on individual outcomes. Furthermore, there are no existing CREMs that can model intrinsically nonlinear growth. The goals of this study are to develop a Bayesian piecewise CREM to model intrinsically nonlinear growth and evaluate what data conditions are necessary to empirically identify both intrinsically linear and nonlinear longitudinal CREMs. This study includes an applied example that utilizes the piecewise CREM with real data and three simulation studies to assess the data conditions necessary to estimate linear, quadratic, and piecewise CREMs. Results show that the number of repeated measurements collected on groups impacts the ability to recover the group effects. Additionally, functional form complexity impacted data collection requirements for estimating longitudinal CREMs.

Sexual Behavior and Perceived Risk for Oropharyngeal Cancer Among Men Who Have Sex With Men: A Psychometric Scale Validation

BACKGROUND

Men who have sex with men (MSM) are at increased risk for human papillomavirus-associated oropharyngeal cancer (HPV-OPC). The objective of this analysis was to create a psychometrically validated scale to measure perception of risk for HPV-OPC.

METHODS

We conducted an exploratory and a confirmatory factor analysis to determine and confirm the latent factor structure. We used a path diagram to evaluate the relationship between the validated scale and perceived risk for HPV-OPC. The model was determined to be a good fit if it met all criteria: root mean square error of approximation ≤0.06, standardized root mean residual ≤0.08, Comparative Fit Index ≥0.90, and Tucker-Lewis Index ≥0.90. We report standardized estimates and 95% confidence intervals.

RESULTS

This cross-sectional study recruited 1315 MSM. A majority (73.33%) of MSM had performed fellatio on ≥20 partners, 36.98% had rimmed ≥20 partners, and 5.31% had performed cunnilingus on ≥10 partners in their lifetime.Six sexual history survey items loaded onto 2 latent factors: sexual risk behaviors: class 1 and sexual risk behaviors: class 2. The final model statistics indicated good fit: root mean square error of approximation = 0.064, standardized root mean residual = 0.059, Comparative Fit Index = 0.996, and Tucker-Lewis Index = 0.993. Sexual risk behaviors: class 1 was associated with greater perceived risk for HPV-OPC (0.217; 95% confidence interval, 0.138-0.295). Age, HIV status, HPV vaccination status, and sexual risk behaviors: class 2 were not associated with perceived risk for HPV-OPC.

CONCLUSION

Men who have sex with men assessed risk for HPV-OPC based on their lifetime number of cisgender male sexual partners, rimming partners, and fellatio partners but not other sexual behaviors. Men who have sex with men may be responsive to future HPV-OPC educational interventions and opportunities for screening.

The need for and acceptability of a curriculum to train nursing and medical students in the sexual healthcare of clients with female genital mutilation/cutting in Tanzania

BACKGROUND

Female genital mutilation/cutting (FGM/C) is tied to one of the most conservative cultures in the Mediterranean and Sub-Saharan Africa. More than 200 million girls and women in 30 African, Asian and the middle Eastern countries have undergone FGM/C. However, healthcare professionals are not adequately trained to prevent and manage FGM/C-related complications including sexual health problems. This study aimed to assess the need and acceptability of a curriculum to train nursing and medical students in the sexual healthcare of clients with FGM/C in Tanzania.

METHODS

We used a descriptive and cross sectional study design to collect and analyse information from 271 medical and 137 nursing students in Tanzania. A Qualtrics online survey was used to obtain quantitative data on training interest, previous training received, and the curriculum delivery method. Open-ended questions were used to explore their insights on significance to obtain the necessary competencies to treat and prevent FGM/C. Descriptive statistics were used to analyze quantitative data while qualitative data were analyzed using a thematic approach.

RESULTS

Almost half of the participants reported they had little to no training in sexual healthcare for women with FGM/C (47%). In all, 82.4% reported the training to be acceptable. Following thematic analysis of open-ended questions, participants expressed a desire to improve their competencies to meet the current and future sexual and psychological health needs of women and girls who have undergone FGM/C.

CONCLUSION

It is a necessary and acceptable to develop a curriculum to train healthcare students to diagnose, treat and prevent sexual health complications related to FGM/C. In our study, designing a culturally sensitive curriculum and its delivery method, that includes practical sessions with simulated patients, was considered the most beneficial and favorable.

A Multidimensional Model to Facilitate Within Person Comparison of Attributes

In psychological research and practice, a person's scores on two different traits or abilities are often compared. Such within-person comparisons require that measurements have equal units (EU) and/or equal origins: an assumption rarely validated. We describe a multidimensional SEM/IRT model from the literature and, using principles of conjoint measurement, show that its expected response variables satisfy the axioms of additive conjoint measurement for measurement on a common scale. In an application to Quality of Life data, the EU analysis is used as a pre-processing step to derive a simple structure Quality of Life model with three dimensions expressed in equal units. The results are used to address questions that can only be addressed by scores expressed in equal units. When the EU model fits the data, scores in the corresponding simple structure model will have added validity in that they can address questions that cannot otherwise be addressed. Limitations and the need for further research are discussed.

Parents of preschoolers use multiple strategies to feed their children: Findings from an observational video pilot study

The current study leveraged observational data collection methods to fill gaps in our understanding of parent approach to feeding as well as child responses to various parental approaches. Specifically, the study aimed to: 1) characterize the broad range of food parenting practices used by parents of preschoolers during shared mealtimes at home, including differences by child gender, and 2) describe child responses to specific parent feeding practices. Forty parent-child dyads participated by recording two in-home shared meals. Meals were coded using a behavioral coding scheme that coded the occurrence of 11 distinct food parenting practices (e.g. indirect and direct commands, praise, bribes) and eight child responses (e.g., eat, refuse, cry/whine) to food parenting practices. Results revealed that parents engaged in a broad range of food parenting practices at meals. On average, parents in our sample used 10.51 (SD 7.83; Range 0-30) total food parenting practices per mealtime with a mean use of 3.38 (SD 1.67; Range 0-8) unique food parenting practices per mealtime. Use of indirect and direct commands to eat were most common; direct and indirect commands were used by 97.5% (n = 39) and 87.5% (n = 35) of parents at meals, respectively. No statistically significant differences were observed by child gender. No one specific feeding practice consistently yielded compliance or refusal to eat from the child, instead child responses were often mixed (e.g., compliance followed by refusal and/or refusal followed by compliance). However, use of praise to prompt eating was the practice that most often resulted in child compliance; 80.8% of children complied following parent's use of praise as a prompt to eat. Findings deepen our understanding of the types and frequency of food parenting practices used by parents of preschoolers during meals eaten at home and illuminate child responses to specific food parenting practices.

The Impact of Functional Form Complexity on Model Overfitting for Nonlinear Mixed-Effects Models

Nonlinear mixed-effects models (NLMEMs) allow researchers to model curvilinear patterns of growth, but there is ambiguity as to what functional form the data follow. Often, researchers fit multiple nonlinear functions to data and use model selection criteria to decide which functional form fits the data "best." Frequently used model selection criteria only account for the number of parameters in a model but overlook the complexity of intrinsically nonlinear functional forms. This can lead to overfitting and hinder the generalizability and reproducibility of results. The primary goal of this study was to evaluate the performance of eight model selection criteria via a Monte Carlo simulation study and assess under what conditions these criteria are sensitive to model overfitting as it relates to functional form complexity. Results highlighted criteria with the potential to capture overfitting for intrinsically nonlinear functional forms for NLMEMs. Information criteria and the stochastic information complexity criterion recovered the true model more often than the average or conditional concordance correlation. Results also suggest that the amount of residual variance and sample size have an impact on model selection for NLMEMs. Implications for future research and recommendations for application are also provided.

Not Lost in Translation: The Use of Standardized Patients Technology among Health Professional Students in Tanzania

Health professionals in Tanzania report a perceived need for sexual and reproductive health communication training to meet patient needs and reduce disparities. Simulation optimizes clinical performance and public entrustment. The study describes the development, feasibility, and acceptability measures of evidence-based, Afrocentric, standardized patient scenarios to train nursing, medical, and midwifery students in sexual and reproductive health in Tanzania. Standardized patient simulation cases with embedded cultural, language, gender, age, sexuality, and legal complexity issues were identified by stakeholders in Dar es Salaam centering on;1) adolescent health, 2) women's health, and 3) male health cases. Twenty-four health professional students evenly split across nursing, midwifery, and medicine were recruited and enrolled to participate in a pilot trial of the standardized patient simulations conducted in Kiswahili and the results recorded. Videos were evaluated by trained bilingual research staff using standardized behavioral checklists. Descriptive statistics and bivariate analyses were used to assess the pilot data. The study found that seventy-five percent (N =18) of baseline participants (N=24) returned for the 3-month follow-up simulation assessment. While not powered for statistical significance, students showed improvement in all cases and a significant improvement in the male erectile dysfunction concerns case for both interpersonal communication (t (17) = -3.445, p < .005) and medical history taking checklist (t(17)= -3.259, p < .005). Further, most students found the opportunity to practice using the simulations helpful or very helpful in their sexual and reproductive health education. It was therefore concluded that preliminary sexual and reproductive health simulation data using standardized patients demonstrated feasibility and acceptability among student participants.

Unrecognized sexual dysfunction in gay and bisexual men after prostate cancer treatment: the antecedents and impact of anodyspareunia

BACKGROUND

Anodyspareunia may be an adverse outcome of prostate cancer (PCa) treatment for gay, bisexual, and other men who have sex with men (GBM).

AIM

The aims of this study were to (1) describe the clinical symptoms of painful receptive anal intercourse (RAI) in GBM following PCa treatment, (2) estimate the prevalence of anodyspareunia, and (3) identify clinical and psychosocial correlates.

METHODS

This was a secondary analysis of baseline and 24-month follow-up data from the Restore-2 randomized clinical trial of 401 GBM treated for PCa. The analytic sample included only those participants who attempted RAI during or since their PCa treatment (N = 195).

OUTCOMES

Anodyspareunia was operationalized as moderate to severe pain during RAI for ≥6 months that resulted in mild to severe distress. Additional quality-of-life outcomes included the Expanded Prostate Cancer Index Composite (bowel function and bother subscales), the Brief Symptom Inventory-18, and the Functional Assessment of Cancer Therapy-Prostate.

RESULTS

Overall 82 (42.1%) participants reported pain during RAI since completing PCa treatment. Of these, 45.1% experienced painful RAI sometimes or frequently, and 63.0% indicated that the pain was persistent. The pain at its worst was moderate to very severe for 79.0%. The experience of pain was at least mildly distressing for 63.5%. Painful RAI worsened for a third (33.4%) of participants after completing PCa treatment. Of the 82 GBM, 15.4% were classified as meeting criteria for anodyspareunia. Antecedents of anodyspareunia included a lifelong history of painful RAI and bowel dysfunction following PCa treatment. Those reporting symptoms of anodyspareunia were more likely to avoid RAI due to pain (adjusted odds ratio, 4.37), which was negatively associated with sexual satisfaction (mean difference, -2.77) and self-esteem (mean difference, -3.33). The model explained 37.2% of the variance in overall quality of life.

CLINICAL IMPLICATIONS

Culturally responsive PCa care should include the assessment of anodyspareunia among GBM and explore treatment options.

STRENGTHS AND LIMITATIONS

This is the largest study to date focused on anodyspareunia among GBM treated for PCa. Anodyspareunia was assessed with multiple items characterizing the intensity, duration, and distress related to painful RAI. The external validity of the findings is limited by the nonprobability sample. Furthermore, the cause-and-effect relationships between the reported associations cannot be established by the research design.

CONCLUSIONS

Anodyspareunia should be considered a sexual dysfunction in GBM and investigated as an adverse outcome of PCa treatment.

Discrimination of Sexual and Gender Minority Patients in Prostate Cancer Treatment: Results from the Restore-1 Study

This study is the first to quantify experiences of discrimination in treatment undertaken by sexual and gender minority prostate cancer patients. Participants were 192 gay and bisexual and one transgender prostate cancer patients living in the US recruited from North America's largest online cancer support group. In this online survey, discrimination in treatment was measured using the Everyday Discrimination Scale (EDS), adapted for medical settings. Almost half (46%) endorsed at least one item, including 43% that the provider did not listen, 25% that they were talked down to, 20% that they received poorer care than other patients, 19% that the provider acted as superior, and 10% that the provider appeared afraid of them. While most (26.3%) rated the discrimination as "rare" or "sometimes" (EDS=1-3), 20% reported it as more common (EDS≥4). Most attributed the discrimination to their sexual orientation, or to providers being arrogant or too pushed for time. Discrimination was significantly associated with poorer urinary, bowel, and hormonal (but not sexual) EPIC function and bother scores, and with poorer mental health (SF-12). Those who had systemic/combined treatment (versus either radiation only or surgery only) were more likely to report discrimination. This study provides the first evidence that discrimination in prostate cancer treatment, including micro-aggressions, appear a common experience for gay and bisexual patients, and may result in poorer health outcomes.

Pain and Loss of Pleasure in Receptive Anal Sex for Gay and Bisexual Men following Prostate Cancer Treatment: Results from the Restore-1 Study

Prostate cancer treatments disrupt receptive anal intercourse (RAI) for gay and bisexual men (GBM). Sexual dysfunction following prostate cancer treatment may include severe pain in the anorectum during RAI (i.e., anodyspareunia). The purpose of this study was to explore the impact of prostate cancer and its treatments on RAI among GBM. Data were from a cross-sectional online survey of 100 GBM prostate cancer survivors who reported pleasurable RAI prior to treatment. Approximately 47% of the sample reported recent RAI, which was more common among GBM in long-term relationships. RAI was also associated with engagement in other sexual behaviors (e.g., oral and insertive anal sex). Anodyspareunia was reported by 23% of the men who had attempted recent RAI. Anodyspareunia was negatively associated with mental health, performing oral sex on a partner, and bowel function. The overwhelming majority received no information from their healthcare providers about loss of RAI function prior to prostate cancer treatment. Culturally responsive cancer survivorship care may need to address the loss of RAI function for GBM prostate cancer survivors.

Prostate cancer disclosure and sexual orientation: Understanding outness to healthcare providers as a situational or consistent phenomenon

OBJECTIVE

In this study, we investigated if outness is more a situational or a consistent characteristic in gay, bisexual, and other men who have sex with men (GBM) treated for prostate cancer and how the disclosure of sexual orientation impacts provider discussions of sexual side effects.

METHODS

Data came from Restore, an online cross-sectional survey of 193 GBM prostate cancer survivors living in North America and were analyzed using various statistical models.

RESULTS

Disclosure of sexual orientation and of living with prostate cancer were not significantly correlated. Participants who were out regarding sexual orientation were more likely to report that their surgeons and urologists discussed the sexual side effects of treatment.

CONCLUSION

Outness appears to be a situational phenomenon. GBM prostate cancer survivors who were out regarding sexual orientation received more discussion surrounding sexual side effects of prostate cancer treatment from their providers.

PRACTICE IMPLICATIONS

It is important for healthcare providers to inquire about patient's sexual orientation to provide holistic care to these patients to address health disparities within this group.

Tailoring a sexual health curriculum to the sexual health challenges seen by midwifery, nursing and medical providers and students in Tanzania

BACKGROUND

 Tanzania is a country experiencing multiple sexual health challenges, but providers receive no formal training in sexual health.

AIM

 This study aimed to assess (1) what sexual health challenges are commonly seen in clinics in Tanzania, (2) which are raised by patients, (3) which are not addressed and (4) which topics to prioritise for a sexual health curriculum.

SETTING

 Healthcare settings in Tanzania.

METHODS

 Participants were 60 experienced and 61 student doctors, nurses and midwives working in Dar es Salaam. The authors conducted 18 focus groups stratified by profession (midwifery, nursing or medicine) and experience (practitioners vs. students).

RESULTS

 Providers identified six common sexual health concerns: (1) Human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) and sexually transmissible infection (STI) (especially syphilis and gonorrhoea), (2) sexual violence (including intimate partner violence and female genital mutilation), (3) early and unwanted pregnancy (including early sexual debut and complications from abortion), (4) sexual dysfunctions, (5) key population concerns (e.g. lesbian, gay, bisexual, transgender (LGBT); sex work) and (6) non-procreative sexual behaviour (including pornography and masturbation in males and oral and anal sex practices in heterosexual couples). Across professions, few differences were observed. Homosexuality, sex work, masturbation and pornography were identified as taboo topics rarely discussed. Most participants (81%) wanted one comprehensive sexual health curriculum delivered across disciplines.

CONCLUSION

 A sexual health curriculum for health students in Tanzania needs to address the most common sexual health concerns of patients. In addition to teaching sexual science and clinical care, skills training in how to address taboo topics is recommended. Students endorsed almost all sexual health topics, which suggests that a comprehensive curriculum is appropriate.

Prevalence and Risk Factors for Sexually Transmitted Infections in Gay and Bisexual Prostate Cancer Survivors: Results From the Restore-2 Study

Background

Equitable cancer survivorship care for gay and bisexual male (GBM) prostate cancer survivors should be responsive to their sexual health needs. Rates of sexually transmitted infections (STIs) are higher among GBM compared to heterosexual men across the lifespan. In addition, evidence suggests that GBM will use a variety of strategies to cope with sexual dysfunction that may increase risk for STIs. The purpose of this study was to determine the prevalence of STIs following prostate cancer treatment among GBM and identify risk factors.

Methods

In 2019, 401 GBM previously treated for prostate cancer were recruited into the Restore-2 Study. They completed a baseline online questionnaire with items assessing STIs diagnosed since being treated for prostate cancer. Any STI diagnoses was regressed on demographic, clinical, and relationship related variables using binary logistic regression.

Results

Forty-five participants (11.4%) were diagnosed with an STI during or following their prostate cancer treatment. The mostly commonly diagnosed STI was syphilis (4.3%), followed by gonorrhoea (2.8%), and chlamydia (2.5%). Four participants were infected with HIV following their prostate cancer treatment. Independent risk factors for STI diagnosis included time since prostate cancer diagnosis (aOR = 1.18; 95% CI: 1.10-1.26), nonmonogamous sexual relationship (aOR = 11.23; 95% CI: 2.11-59.73), better sexual function (aOR = 1.02; 95% CI: 1.01-1.04), penile injection treatment (aOR = 3.28; 95% CI: 1.48-7.29), and multiple sex partners (aOR = 5.57; 95% CI: 1.64-18.96).

Conclusions

GBM prostate cancer survivors are at risk for STIs. Culturally responsive STI prevention should be incorporated into cancer survivorship plans, particularly as men are treated for and regain sexual function over time.

Racial/Ethnic Differences in Health-Related Quality of Life Among Gay and Bisexual Prostate Cancer Survivors

Introduction

Prostate cancer treatment has established effects on the health-related quality of life (HRQOL) of patients. While racial/ethnic differences in HRQOL have been explored in heterosexual patients, this is the first study to examine racial/ethnic differences in a cohort of sexual minority prostate cancer survivors.

Methods

We used data from the Restore-1 study, an online cross-sectional survey of sexual and gender minority (SGM) prostate cancer survivors in North America, to explore the association between race/ethnicity and HRQOL. General mental and physical HRQOL was assessed using the Short-Form Health Survey version 2 (SF-12). The frequency and distress of prostate cancer specific symptoms was assessed using the Expanded Prostate Cancer Composite (EPIC) scale. Multivariable linear regression was used to estimate mean differences in HRQOL between sexual minority men of color and their white, non-Hispanic counterparts after adjustment for pertinent demographic and medical characteristics.

Results

Among 190 participants, 23 (12%) self-identified as non-white and/or Hispanic. In unadjusted analysis, sexual minority men of color compared to their white counterparts reported worse HRQOL scores in the EPIC hormonal summary (73.8 vs. 81.8) and hormonal function (70.9 vs 80.5) domains. Clinically important differences between men of color and their white counterparts were seen in the EPIC bowel function (mean difference (MD): -4.5, 95% CI: -9.9, 0.8), hormonal summary (MD: -8.0, 95% CI: -15.6, -0.4), hormonal function (MD: -9.6, 95% CI: -17.6, -1.6), and hormonal bother (MD: -6.7, 95% CI: -14.4, 1.1) domains. After adjustment for covariates, clinically important differences persisted between men of color and white, non-Hispanic men on the hormonal summary (74.4 vs. 81.7), hormonal function (71.3 vs. 80.3), and hormonal bother (77.0 vs. 82.7) domains.

Conclusions

This exploratory study provides the first evidence that sexual minority men of color may have worse HRQOL outcomes compared to white, non-Hispanic sexual minority men following prostate cancer treatment.

Recruiting an underserved, difficult to reach population into a cancer trial: Strategies from the Restore-2 Rehabilitation Trial for gay and bisexual prostate cancer patients

BACKGROUND/AIMS

Sexual minorities are small and under-researched populations that are at disproportionate risk for cancer and poor cancer outcomes. Described as a "hidden population," the principal research challenge has been to develop effective methods to identify and recruit such cancer patients into cancer studies. Online recruitment strategies, as well as targeted clinic recruitment using patient-entered sexual orientation and gender identity data from electronic medical records have potential to transform recruitment, but studies testing the effects of how to recruit using these have not been published.

METHODS

In 2019, we conducted a naturalistic, three-arm, stratified prospective study to compare three recruitment strategies: (a) clinic based recruitment of prostate cancer patients from gay health and urology clinics; (b) directly from the gay community; and (c) online recruitment (through cancer support, sex/dating, and social sites). For each strategy, we estimated time, workload, and direct costs involved. To study how recruitment strategy may affect sampling, we tested for retention rates, demographic and outcome differences across sites. Using these methods, we successfully recruited 401 gay and bisexual prostate cancer patients into a randomized, controlled, 24-month trial testing an online sexual and urinary rehabilitation curriculum tailored for this population.

RESULTS

There were seven key results. First, it is possible to recruit substantial numbers of sexual minority men into prostate cancer studies provided online recruitment methods are used. Second, we observed big differences in dropout during study onboarding by recruitment source. Third, within online recruitment, the online sex/dating application (app) was the most successful and efficient, followed by the cancer support site, and then the social networking site. Fourth, while clinics were the cheapest source of recruitment, they were time intensive and low in yield. Fifth, the cancer support site and sex/dating app recruits differed by several characteristics, with the former being more rehabilitation-focused while the latter were younger and more sexually active. Sixth, we found almost no differences in outcomes across the three online recruitment sites. Seventh, because retention in online studies has been a concern, we confirm very low attrition at 3- and 6 months into the trial.

CONCLUSION

For sexual minority cancer research, more research on how to use sexual orientation and gender identity electronic medical record data for clinic-based recruitment is needed. For other small or hard-to-reach populations, researchers should compare and publish online versus offline recruitment strategies.

Creation and Psychometric Validation of the Sexual Minorities and Prostate Cancer Scale (SMACS) in Sexual Minority Patients-The Restore-2 Study

BACKGROUND

Existing measures of sexual functioning in prostate cancer survivors focus primarily on erectile function and do not adequately measure the experiences of sexual minority men.

AIM

To develop and psychometrically evaluate a new scale to measure sexual functioning among sexual minority men with prostate cancer.

METHODS

Sexual minority prostate cancer patients (n = 401) completed an online battery of urinary and sexual functioning tests in 2019, including a new 37-item instrument about their sexual functioning post-treatment for prostate cancer.

OUTCOMES

We used confirmatory factor analysis to determine the construct validity of a new scale including five subscales: a four-factor model for all participants (n = 401) evaluated Sexual Satisfaction, Sexual Confidence, Frequency of Sexual Problems, and Urinary Incontinence in Sex. A single-factor model completed only by participants who had attempted or desired receptive anal sex (n = 255) was evaluated in the fifth subscale: Problematic Receptive Anal Sex. To evaluate criterion validity, we calculated the intercorrelations between each Sexual Minorities and Prostate Cancer Scale (SMACS) subscale and four related scales: the Expanded Prostate Cancer Index Composite-50 (EPIC), the Functional Assessment of Cancer Therapy-Prostate, the Brief Symptom Inventory-18, and the International Consultation on incontinence questionnaire. Cronbach's alphas were calculated to measure internal consistency (ie, reliability).

RESULTS

Cronbach's alpha values ranged from 0.64 to 0.89. Loadings (0.479-0.926) and model fit indices were strong (Root Mean Square Error of Approximation: 0.085, Standardized root mean squared residual: 0.063, comparative fit index: 0.927, Tucker-Lewis Index: 0.907). For criterion validity, Sexual Satisfaction, Sexual Confidence, and Frequency of Sexual Problems were moderately correlated with EPIC function and bother scores (r = 0.50-0.72) and Urinary incontinence in sex correlated moderately with EPIC Urinary Function and International Consultation on incontinence questionnaire scores (0.45-0.56).

CLINICAL IMPLICATIONS

The SMACS can be used by clinicians and researchers to comprehensively measure sexual functioning in sexual minority men, in conjunction with existing scales.

STRENGTHS AND LIMITATIONS

This new scale is validated in a large, geographically diverse cohort of sexual minority cancer survivors and fills an important gap in existing measures of sexual functioning. Limitations include a lack of a validation sample.

CONCLUSION

The SMACS is a valid and reliable new scale that measures sexual minority men's experience of urinary incontinence in sex, problematic receptive anal sex, and sexual distress. Polter EJ, Kohli N, Rosser BRS, et al. Creation and Psychometric Validation of the Sexual Minorities and Prostate Cancer Scale (SMACS) in Sexual Minority Patients-The Restore-2 Study. J Sex Med 2022;19:529-540.

Health Disparities of Sexual Minority Patients Following Prostate Cancer Treatment: Results From the Restore-2 Study

PURPOSE

The NIH has identified sexual and gender minority persons as a health disparity population but little is known about cancer outcomes in these populations. The purpose of this study was to identify disparities in sexual minority prostate cancer patient-reported outcomes, to examine within group differences, and to test for alternative explanations for identified differences.

MATERIALS AND METHODS

In 2019, we recruited 401 gay and bisexual prostate cancer patients into the Restore-2 study, a randomized controlled trial of rehabilitation program tailored for sexual minority men.

RESULTS

Compared to the normative (heterosexual) EPIC sample, participants had significantly worse urinary, bowel and hormonal function, better sexual function, and no difference on bother scores. They also had worse depression and overall mental health, and worse physical, social/family, functional, prostate specific and overall well-being quality of life outcomes. Across measures, no differences by age, gay versus bisexual orientation, race/ethnicity, and relationship status were observed. Those who had hormonal treatment had worse sexual and hormonal function than those who had radiation or surgery only. Those with a longer time since treatment had better urinary function. Differences remained when participants were matched to normative samples on cancer stage and time since treatment.

CONCLUSIONS

This, the largest study of sexual minority prostate cancer patients to date, confirms health disparities in prostate cancer quality of life outcomes. Findings appear reliable and robust. To improve the clinical care of prostate cancer, it will be important to address the health disparities experienced by sexual minority prostate cancer patients.

Comorbidity Prevalence and Impact on Quality of Life in Gay and Bisexual Men Following Prostate Cancer Treatment

Introduction

Studies have demonstrated worse health related quality of life (HRQOL) outcomes in gay and bisexual men (GBM) following prostate cancer treatment compared to heterosexual men potentially due to differences in comorbidity burden.

Aim

To establish the prevalence of comorbidities and their association with HRQOL metrics in GBM following prostate cancer treatment.

Methods

We evaluated HRQOL and prevalence of comorbidities in 193 GBM from the United States and Canada in a cross-sectional, online survey: the Masked for Review. HRQOL was measured with the Expanded Prostate Cancer Index Composite (EPIC) and the 12-Item Short Form Health Survey (SF-12).

Main Outcome Measures

Our outcomes included comorbidity prevalence, mean differences for HRQOL scores by comorbidity status, and mean differences for HRQOL by comorbidity count.

Results

GBM were found to have a higher prevalence of blood vessel disease and mental health disorders but lower prevalence of obesity and type 2 diabetes when compared to published data in general prostate cancer populations. Statistically significant reductions in HRQOL metrics were associated with mental health diagnoses, diabetes, and obesity. Increased number of comorbidities was also associated with reductions in HRQOL metrics in nearly all categories.

Conclusion

These results suggest that the worse QOL outcomes in GBM following prostate cancer treatment may be due to differences in comorbidity burden. This study is the first to evaluate the relationship between comorbidities and HRQOL outcomes in GBM. Limitations of this study include a small sample size and cross-sectional study design. If confirmed in larger, longitudinal, clinically confirmed studies, these findings indicate a need to intervene on and consider comorbidities in GBM diagnosed with prostate cancer.

Haggart R, Polter E, Ross M, et al. Comorbidity Prevalence and Impact on Quality of Life in Gay and Bisexual Men Following Prostate Cancer Treatment. Sex Med 2021;9:100439.

Every urologist and oncologist should know about treating sexual and gender minority prostate cancer patients: translating research findings into clinical practice

In 2016, the NIH designated sexual and gender minorities (SGM) a health disparity population. The next year, the American Society of Clinical Oncology highlighted the need to improve the suboptimal cancer and survivorship care received by SGM populations. There are currently no evidence-based training programs in culturally competent care of prostate cancer patients who are gay, bisexual and/or transgender. In this selective review, we summarize findings from the largest quantitative studies focused on sexual minority prostate cancer survivors and from 65 interviews with NIH staff, clinicians, and cancer clinics in 11 US cities. The report is divided into three parts and uses a question and answer format to address 21 questions relevant to clinicians providing care to SGM prostate cancer patients. First, we identify population-specific issues that are culturally relevant in the care of SGM patients with prostate cancer. While a body of research has emerged on sexual minority prostate cancer patients, the literature on gender minorities is limited to single case reports and inadequate to inform practice. This review covers definitions, population size, cultural and historical context, sexual behavior, population invisibility, sexual orientation and gender identity (SOGI) in the electronic medical record, disparities and evidence of discrimination in treatment provision. The second part focuses on promoting evidence-informed, patient-centered care. This includes current practices in assessing sexual orientation, management of disclosure of sexual orientation, how to address common problems sexual minority men experience post-treatment, common questions sexual minority patients have, management of urinary incontinence, HIV and STI risk during and post-treatment, and sub-groups of sexual minority patients with worse outcomes. It then identifies how male partners differ in prostate cancer support, current research on rehabilitation for sexual minority men, issues in advanced prostate cancer, and things to avoid with minority patients. Finally, we examine the cultural divide between provider and patient, advocating for cultural humility when working with minority patients. Training programs and continuing education can help providers both to become more aware of their own cultural assumptions, informed about health disparities, and able to provide quality care, and to make clinics more welcoming to SGM patients.

Addressing Quantitative and Qualitative Hypotheses Using Regression Models with Equality Restrictions and Predictors Measured in Common Units

In regression, some or all of the predictors may be measured in common units: e.g. X₁ = carbohydrate calories, X₂ = protein calories, X₃ = fat calories. Such predictors can occur in disciplines as diverse as business, economics, education, medicine, nutrition, psychology, sport science, etc. Predictors in common units can lead to unique quantitative and qualitative hypotheses that can be addressed by imposing equality restrictions on the regression weights (e.g. b1=b2=b3). A simple device, total score substitution, is available for constraining regression coefficients to be equal in a variety of regression applications. Applications to linear, moderated linear, and polynomial models are described, but extensions to generalized linear models and multilevel linear models are also possible. Total score substitution in linear and moderated regression is illustrated using high school coursework and mathematics achievement data. Data, code (R, SPSS, SAS), and output are publicly available.

Item and scale properties of the Oral Health Literacy Adults Questionnaire assessed by item response theory

OBJECTIVES

a) To evaluate the item and scale properties of the Oral Health Literacy Adults Questionnaire (OHL-AQ) in an adult general population. b) To determine precision or accuracy of the respondents' estimated scores along the Oral Health Literacy (OHL) spectrum using item response theory (IRT) modeling.

METHODS

Survey data were collected from a convenience sample of 405 adult attendees of the 2014 Minnesota State Fair. We used the two-parameter logistic (2PL) model for the item response theory (IRT) analyses of OHL-AQ data and calibrated items to estimate model-based item difficulty and discrimination parameters. Item and scale properties were also assessed by plotting and interpreting item characteristic curves (ICCs), test characteristic curve (TCC), and test information function (TIF).

RESULTS

Based on interpretation of model coefficients, statistical testing, and model fit criteria, we deemed the 2PL model superior and selected this model to examine item and scale properties. Scale reliability was shown to be good through the test information function (TIF). TIF from our analysis showed that higher levels of OHL were measured less precisely than lower levels of OHL.

CONCLUSION

We demonstrated OHL-AQ as a whole has promising psychometric properties. However, for equiprecise measurement across the scale range, the scale needs more items for measuring higher levels of OHL.

Bayesian modeling of associations in bivariate piecewise linear mixed-effects models

Longitudinal processes rarely occur in isolation; often the growth curves of 2 or more variables are interdependent. Moreover, growth curves rarely exhibit a constant pattern of change. Many educational and psychological phenomena are comprised of different developmental phases (segments). Bivariate piecewise linear mixed-effects models (BPLMEM) are a useful and flexible statistical framework that allow simultaneous modeling of 2 processes that portray segmented change and investigates their associations over time. The purpose of the present study was to develop a BPLMEM using a Bayesian inference approach allowing the estimation of the association between the error variances and providing a more robust modeling choice for the joint random-effects of the 2 processes. This study aims to improve upon the limitations of the prior literature on bivariate piecewise mixed-effects models, such as only allowing the modeling of uncorrelated residual errors across the 2 longitudinal processes and restricting modeling choices for the random effects. The performance of the BPLMEM was investigated via a Monte Carlo simulation study. Furthermore, the utility of BPLMEM was illustrated by using a national educational dataset, Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K), where we examined the joint development of mathematics and reading achievement scores and the association between their trajectories over 7 measurement occasions. The findings obtained shed new light on the relationship between these 2 prominent educational domains over time. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Sexual Functioning of Gay and Bisexual Men Following Prostate Cancer Treatment: Results from the Restore Study

Prostate cancer is the second most common cancer in gay, bisexual, and other men who have sex with men (GBM). Few studies have assessed the effects of treatment on GBM's sexual behavior. For an online survey, 193 gay and bisexual men with prostate cancer were recruited from the North American's largest online cancer support group. Sexual functioning was measured using the Expanded Prostate Cancer Index Composite (EPIC) and a tailored Gay Sexual Functioning Inventory (GSFI). GBM have worse EPIC urinary and hormonal function and worse hormonal bother, but better sexual function and bother scores than published norms. In the GSFI, two-thirds of participants described their sexual functioning, post-treatment, as fair to poor. Only 22% reported erections sufficient for insertive anal sex. For receptive anal sex, one-third met criteria for anodyspareunia. Over half reported urination problems during sex or at orgasm. Erectile difficulties were common, severe, and a reason cited for not using condoms. Three men HIV seroconverted post-prostate cancer treatment. Differences in function and bother scores were observed by type of treatment, age, race/ethnicity, sexual orientation, but not relationship status. Sexual functioning significantly predicted long-term mental and physical health. GBM scored significantly worse on mental health and better on physical health than published norms. Sexual recovery after prostate cancer treatment is problematic for most GBM. Research to develop more effective sexual recovery, tailored to the needs of GBM treated for prostate cancer, is needed. Six implications for clinicians treating GBM with prostate cancer are identified.

Abstract B037: The role of HIV status in health-related quality of life in gay and bisexual prostate cancer survivors: Findings from the Restore study

Objective: Prostate cancer is the most common invasive cancer in gay and bisexual men. Despite the unique sexual and urinary concerns of this group, nearly all studies of prostate cancer rehabilitation post-treatment have focused on heterosexual men. Older gay and bisexual men, the generation most likely to experience prostate cancer, also have high prevalence of human immunodeficiency virus (HIV), which is associated with lower quality of life. Research has indicated that people with HIV may experience health disparities in cancer treatment, but to our knowledge, this is the first quantitative study of the association between HIV status and health-related quality of life (HRQOL) in gay and bisexual men with prostate cancer.

Methods: Data from the Restore study, a cross-sectional online survey of gay and bisexual men treated for prostate cancer and residing in the United States or Canada, were used to examine this association. The Expanded Prostate Cancer Index Composite (EPIC) was used to assess function and bother in four domains: urinary, sexual, bowel, and hormone. Overall physical and mental HRQOL was assessed utilizing the SF-12 Health Survey. Multivariate analysis of variance (MANOVA) was used to evaluate the association between HIV status and HRQOL scores. Models were adjusted for age, race, treatment (prostatectomy, radiation, or advanced treatment), relationship status (partnered/married versus single/dating/widowed/divorced), preferred role in sex, and number of comorbidities.

Results: Of 193 participants, 24 (12.4%) reported an HIV diagnosis, including 3 diagnosed after their prostate cancer treatment. The cohort was 89 percent white, with mean age 63.4 years. After adjustment for demographic and treatment characteristics, HIV-positive status was associated with lower scores on the EPIC urinary (RD: -10.8, 95% CI: -19.5 to -2.2) and sexual (RD: -10.3, 95% CI: -20.2 to -0.4) domains. Although there were no statistically significant associations found in the other domains, HIV-positive participants reported lower outcomes in all domains except the SF-12 mental domain (RD: 0.3, 95% CI: -5.0 to 5.6).

Conclusion: Our findings, though imprecise, provide evidence that HIV status may be associated with poorer HRQOL in gay and bisexual prostate cancer survivors.

Citation Format: Elizabeth J. Polter, Christopher W. Wheldon, Nidhi Kohli, B. R. S. Rosser. The role of HIV status in health-related quality of life in gay and bisexual prostate cancer survivors: Findings from the Restore study [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B037.

0820 Meta-Analysis of the Association of Age and Actigraphy-Assessed Sleep Across the Lifespan

Introduction

Sleep quantity and continuity vary across the lifespan. Actigraphy is reliable, ecologically valid, and is the most widely-used behavioral measure of sleep in research and personal health monitoring. The extent to which age is associated with actigraphy-assessed sleep has not been evaluated across the lifespan. The aim of this meta-analysis was to evaluate the associations between age and actigraphy-assessed sleep in relatively healthy individuals.

Methods

A systematic search of PubMed, Embase.com, Cochrane CENTRAL, and PsycINFO using “actigraphy” and “sleep” terms provided 7,079 titles/abstracts, which were screened to exclude studies of only individuals with mental health disorders, medical conditions, sleep disorders, or shift workers. We evaluated 1,379 full-text articles for reports on the association between age and actigraphy-assessed sleep duration, efficiency, timing, and/or regularity. Overall, 88 articles met these criteria (182 effect sizes; N=18,443). Four meta-analyses were conducted, examining sleep duration (k=86), sleep efficiency (k=58), bedtime (k=27), and wake-up time (k=11). There were insufficient numbers of studies (less than 5) to evaluate sleep midpoint or sleep regularity. We tested continent of the study, study design, actigraphy device type, and number of nights of data collection as moderators of meta-analytic associations.

Results

With increasing age, sleep duration was shorter (r = -0.13) and sleep efficiency was lower (r = -0.06). Bedtime was later with age for ages 6-21 (r = 0.31) and earlier for ages 22 and up (r = -0.65). Wake-up time was not associated with age for ages 6-21 (r = 0.20) but was earlier with increasing age for ages 22 and up (r = -0.71). The strength of these associations was modified by continent and study design, but not by type of actigraphy device or number of nights of data collection.

Conclusion

Weak associations between age and actigraphy-assessed duration and efficiency suggest that inadequate sleep quantity or poor sleep continuity should not be dismissed as typical consequences of aging. Large associations between age and sleep timing, despite a small literature, highlights a promising area for further study, particularly to determine the age at which sleep timing shifts from delaying to advancing.

Support

MAB was supported by T32 HL07560.

The Identification of Family Social Environment Typologies Using Latent Class Analysis: Implications for Future Family-Focused Research

The family social environment is the first environment that a child experiences and has implications for children's health. However, the majority of family social environment measures do not account for its complexity. There is a need for novel approaches for assessing the family social environment that transcends the traditional way of measuring family composition and interaction. The purpose of this secondary data analysis research was to identify distinct family social environment typologies that consider both family composition and interaction and to describe the characteristics of the identified family social environment typologies. A series of latent class analysis results indicated three distinct typologies of family social environment with significant differences in family composition, family problem-solving skills, and demographic characteristics. The process used to identify the typologies and significant differences between the typologies showcases how the field could advance family-focused research by considering family composition and interaction.

Understanding Prostate Cancer in Gay, Bisexual, and Other Men Who Have Sex with Men and Transgender Women: A Review of the Literature

PURPOSE OF REVIEW

a)Prostate cancer in sexual and gender minorities is an emerging medical and public health concern. The purpose of this review is to summarize the state of the science on prostate cancer in gay, bisexual, and other men who have sex with men (GBM) and transgender women (TGW). We undertook a literature review of all publications on this topic through February 2017. With 88 unique papers (83) on prostate cancer in GBM and 5 case reports of prostate cancer in TGW), a small but robust literature has emerged.

RECENT FINDINGS

b)The first half of this review critiques the literature to date, identifying gaps in approaches to study. The second half summarizes the key findings in eleven areas. In light of this admittedly limited literature, GBM appear to be screened for prostate cancer less than other men, but they are diagnosed with prostate cancer at about the same rate.

SUMMARY

c)Compared to other men, GBM have poorer urinary, bowel, and overall quality-of-life outcomes but better sexual outcomes after treatment; all these findings need more research. Prostate cancer in TGW remains rare and under researched, as the literature is limited to single-case clinical reports.

Health-related quality of life by human immunodeficiency virus status in a cross-sectional survey of gay and bisexual prostate cancer survivors

OBJECTIVE

Prostate cancer is the most common invasive cancer in gay and bisexual men (GBM). Despite the unique sexual and urinary concerns of this group, studies of prostate cancer rehabilitation have primarily focused on heterosexual men. GBM also have high prevalence of human immunodeficiency virus (HIV), which may be associated with lower health-related quality of life (HRQOL). We examined the association between HIV status and HRQOL in a cohort of GBM with prostate cancer.

METHODS

Data from the Restore study, a cross-sectional online survey of GBM treated for prostate cancer, were used to examine this association. The Expanded Prostate Cancer Index Composite (EPIC) assessed function, bother, and summary measures in four domains: urinary, sexual, bowel, and hormone. Overall physical and mental HRQOL was assessed using the Short-Form Health Survey (SF-12). Multivariate analysis of variance and linear regression were used to evaluate the association between HIV status and HRQOL scores after adjustment for demographic and sexual characteristics.

RESULTS

Of 192 participants, 24 (12.4%) reported an HIV diagnosis. After adjustment for covariates, HIV-positive status was associated with lower scores on the EPIC urinary (mean difference [MD]: -13.0, 95% CI, -21.4 to -4.6), sexual (MD: -12.5, 95% CI, -21.9 to -3.2), and bowel (MD: -5.9, 95% CI, -11.7 to -0.2) domains. No significant associations were observed between HIV status and other outcomes.

CONCLUSIONS

HIV status may be associated with poorer urinary, sexual, and bowel HRQOL in GBM prostate cancer survivors.

A Psychometric Analysis of the Algebra and Precalculus Concept Readiness Assessment for Community Colleges

Understanding students’ readiness for precalculus and calculus at the community college level is critical not only because of the key role community colleges play in higher education but also because calculus remains a gateway course for students in advancing to higher level mathematics. The Algebra and Precalculus Concept Readiness Assessment for Community Colleges (APCR-CC) was designed to investigate community college students’ quantitative reasoning abilities and conceptual understanding in algebra. The present study investigates the psychometric properties of the APCR-CC instrument using item response theory based on a sample of intermediate and college algebra students from six community colleges collected in a pretest ( N = 1,131) and posttest ( N = 772) setting. We examine unidimensionality, item fit, local item independence, measurement invariance, and sensitivity to instruction. Our findings suggest that the APCR-CC instrument is sufficiently characterized by one underlying construct, local dependence does not seem to be an issue, and 80% of the items in the APCR-CC instrument are sensitive to instruction.

Influence of Socioecomomic and Oral Health Status on Acceptability of Dental Therapists' Oral Health Care

This study explored the acceptability of dental therapists by respondents' socioeconomic factors and oral health status.

METHODS

Data were collected from 405 adults during the 2014 Minnesota State Fair through completion of an electronic questionnaire and a modified Basic Screening Survey (BSS).

RESULTS

This study found no relevant and statistically significant relationships between a respondent's various socioeconomic factors and their acceptability of care provided by a dental therapist. It also demonstrated no association between participants' perceived or physical oral health status and their acceptability of care provided by a dental therapist.

CONCLUSIONS

The acceptability of care provided by a dental therapist is neither related to socioeconomic characteristics nor perceived or physical oral health.

PRACTICAL IMPLICATIONS

While advancing the acceptability of dental therapists faces many challenges, the patient's socioeconomic profile and his/her oral health status are not among them.

Linear-linear piecewise growth mixture models with unknown random knots: A primer for school psychology

Studying change over time requires rigorous and sometimes novel statistical methods that can support increasingly complex applied research questions. In this article, we provide an overview of the potential of piecewise growth mixture models. This type of longitudinal model can be used to advance our understanding of group and individual growth that may follow a segmented, or disjointed, pattern of change, and where the data come from a mixture of two or more latent classes. We then demonstrate the practical utility of piecewise growth mixture models by applying it to a subsample of students from the Early Childhood Longitudinal Study - Kindergarten Cohort of 1998 (ECLS-K) to ascertain whether mathematics achievement is characterized by one or two latent classes akin to students with and without mathematics difficulties. We discuss the applicability for school psychological research and provide supplementary online files that include an instructional sample dataset and corresponding R routine with explanatory annotations to assist in understanding the R routine before applying this approach in novel applications (https://doi.org/10.1016/j.jsp.2019.03.004).

Detecting Multiple Random Changepoints in Bayesian Piecewise Growth Mixture Models

Piecewise growth mixture models are a flexible and useful class of methods for analyzing segmented trends in individual growth trajectory over time, where the individuals come from a mixture of two or more latent classes. These models allow each segment of the overall developmental process within each class to have a different functional form; examples include two linear phases of growth, or a quadratic phase followed by a linear phase. The changepoint (knot) is the time of transition from one developmental phase (segment) to another. Inferring the location of the changepoint(s) is often of practical interest, along with inference for other model parameters. A random changepoint allows for individual differences in the transition time within each class. The primary objectives of our study are as follows: (1) to develop a PGMM using a Bayesian inference approach that allows the estimation of multiple random changepoints within each class; (2) to develop a procedure to empirically detect the number of random changepoints within each class; and (3) to empirically investigate the bias and precision of the estimation of the model parameters, including the random changepoints, via a simulation study. We have developed the user-friendly package BayesianPGMM for R to facilitate the adoption of this methodology in practice, which is available at https://github.com/lockEF/BayesianPGMM . We describe an application to mouse-tracking data for a visual recognition task.

Social Support and Health-Related Quality of Life Among Gay and Bisexual Men With Prostate Cancer

OBJECTIVES

To describe social support patterns of gay and bisexual men with prostate cancer (GBMPCa) and how social support is associated with prostate cancer outcomes.

SAMPLE & SETTING

A cross-sectional online survey with 186 GBMPCa recruited from a national cancer support group network.

METHODS & VARIABLES

Descriptive statistics of social support and linear regression of social support on general and prostate cancer-specific quality of life (QOL). Social support and health-related QOL were assessed generally and specific to prostate cancer.

RESULTS

Participants primarily relied on partners or husbands, gay and bisexual friends, chosen family, and men from support groups for support. The most common types of support received were informational and emotional social support. Low general social support was significantly associated with worse prostate cancer symptom bother and general mental QOL. Wanting more social support was significantly associated with worse prostate cancer-specific and general QOL.

IMPLICATIONS FOR NURSING

Clinicians should be aware of the different social support networks and needs of GBMPCa and refer them to relevant support groups to improve QOL.

Addressing Participant Validity in a Small Internet Health Survey (The Restore Study): Protocol and Recommendations for Survey Response Validation

Background

While deduplication and cross-validation protocols have been recommended for large Web-based studies, protocols for survey response validation of smaller studies have not been published.

Objective

This paper reports the challenges of survey validation inherent in a small Web-based health survey research.

Methods

The subject population was North American, gay and bisexual, prostate cancer survivors, who represent an under-researched, hidden, difficult-to-recruit, minority-within-a-minority population. In 2015-2016, advertising on a large Web-based cancer survivor support network, using email and social media, yielded 478 completed surveys.

Results

Our manual deduplication and cross-validation protocol identified 289 survey submissions (289/478, 60.4%) as likely spam, most stemming from advertising on social media. The basic components of this deduplication and validation protocol are detailed. An unexpected challenge encountered was invalid survey responses evolving across the study period. This necessitated the static detection protocol be augmented with a dynamic one.

Conclusions

Five recommendations for validation of Web-based samples, especially with smaller difficult-to-recruit populations, are detailed.

Preliminary clinical assessment and non- toxicity evaluation of an ayurvedic formulation BGR-34 in NIDDM

In view of the overall health impact of NIDDM, inventers understand the necessity of improving glycemic control in adults with type 2 diabetes. BGR-34 provides an effective treatment option for adults with type 2 diabetes who have been inadequately controlled on lifestyle with or without other oral hypoglycemic agents (OHGAs) such as metformin, sulfonylurea, or a glitazones. BGR-34 is an appropriate option to consider for addition to a managed care drug formulary. Treatment with BGR-34 produced clinically relevant and statistically significant reductions in all three key measures of glucose control studied -FPG, PPBG and HbA1c- when compared with placebo. BGR-34, showed the promising result with respect to glycemic parameters in NIDDM patient with a significant reduction in fasting blood sugar by 34.3%, postprandial blood sugar 35.5% & glycosylated haemoglobin by 20.31% as compared to placebo group showing a reduction by 13.2%, 10.9% & 10.87% respectively. The trial has also been registered to CTRI, India. This study has been registered in the clinical trial registry-India.

A note on estimating single-class piecewise mixed-effects models with unknown change points

Piecewise mixed-effects models are useful for analyzing longitudinal educational and psychological data sets to model segmented change over time. These models offer an attractive alternative to commonly used quadratic and higher-order polynomial models because the coefficients obtained from fitting the model have meaningful substantive interpretation. The current study thus focuses on the estimation of piecewise mixed-effects model with unknown random change points using maximum likelihood (ML) as described in Du Toit and Cudeck (2009). Previous simulation work (Wang & McArdle, 2008) showed that Bayesian estimation produced reliable parameter estimates for the piecewise model in comparison to frequentist procedures (i.e., first-order Taylor expansion and the adaptive Gaussian quadrature) across all simulation conditions. In the current article a small Monte Carlo simulation study was conducted to assess the performance of the ML approach, a frequentist procedure, and the Bayesian approach for fitting linear–linear piecewise mixed-effects model. The obtained findings show that ML estimation approach produces reliable and accurate estimates under the conditions of small residual variance of the observed variables, and that the size of the residual variance had the most impact on the quality of model parameter estimates. Second, neither ML nor Bayesian estimation procedures performed well under all manipulated conditions with respect to the accuracy and precision of the estimated model parameters.

Evaluation of an assessment instrument for a sexual health curriculum for nurses and midwifery students in Tanzania: The sexual health education for professionals scale (SHEPS)

We assessed the structure and content of a new scale, the SHEPS, to assess change in sexual health confidence, knowledge and attitudes in nursing and midwifery students following an intervention (a 2-day standardized workshop on sexual health). Students were 78 Tanzanian nursing and midwifery students attending a University of Health Sciences, who were assessed immediately before and after the workshop on matched pre- and post-workshop questionnaires. Data confirmed significant changed pre- and post-test on knowledge and confidence on topics taught in the workshop, with the effect also extending to some topics not or minimally covered, suggesting that there was a general increase in confidence and a perception of increased knowledge following the workshop. There was power to detect differences even with a moderate sized matched sample. Correlations between knowledge and confidence on the same content items were between 0.52 and 0.63, suggesting that respondents could clearly distinguish between knowledge and confidence. There were no significant differences pre- and post-test on several controversial cultural and religious attitudes including on abortion and non-vaginal penetrative sex. Alpha coefficients were 0.93 for pre-test and 0.90 for post-test. This field test demonstrates the preliminary appropriateness of the SHEPS as a tool for evaluating sexual health interventions in health care workers.

Predictive Models in Differentiating Vertebral Lesions Using Multiparametric MRI

BACKGROUND AND PURPOSE

Conventional MR imaging has high sensitivity but limited specificity in differentiating various vertebral lesions. We aimed to assess the ability of multiparametric MR imaging in differentiating spinal vertebral lesions and to develop statistical models for predicting the probability of malignant vertebral lesions.

MATERIALS AND METHODS

One hundred twenty-six consecutive patients underwent multiparametric MRI (conventional MR imaging, diffusion-weighted MR imaging, and in-phase/opposed-phase imaging) for vertebral lesions. Vertebral lesions were divided into 3 subgroups: infectious, noninfectious benign, and malignant. The cutoffs for apparent diffusion coefficient (expressed as 10^-3 mm²/s) and signal intensity ratio values were calculated, and 3 predictive models were established for differentiating these subgroups.

RESULTS

Of the lesions of the 126 patients, 62 were infectious, 22 were noninfectious benign, and 42 were malignant. The mean ADC was 1.23 ± 0.16 for infectious, 1.41 ± 0.31 for noninfectious benign, and 1.01 ± 0.22 mm²/s for malignant lesions. The mean signal intensity ratio was 0.80 ± 0.13 for infectious, 0.75 ± 0.19 for noninfectious benign, and 0.98 ± 0.11 for the malignant group. The combination of ADC and signal intensity ratio showed strong discriminatory ability to differentiate lesion type. We found an area under the curve of 0.92 for the predictive model in differentiating infectious from malignant lesions and an area under the curve of 0.91 for the predictive model in differentiating noninfectious benign from malignant lesions. On the basis of the mean ADC and signal intensity ratio, we established automated statistical models that would be helpful in differentiating vertebral lesions.

CONCLUSIONS

Our study shows that multiparametric MRI differentiates various vertebral lesions, and we established prediction models for the same.

Psychometric properties of the English version of the Oral Health Literacy Adults Questionnaire - OHL-AQ

Objective

To test the psychometric properties of the Oral Health Literacy Adult Questionnaire (OHL-AQ) in English. The OHL-AQ was designed to test functional oral health literacy in general populations and was initially validated in Iran.

Methods

The instrument was administered to 405 adult subjects (mean age 45 (SD 16) years and 67% female) attending the 2014 Minnesota State Fair. The OHL-AQ is composed of 17 items measuring four conceptual dimensions: reading comprehension, numeracy, listening, and decision-making. Participants selected the best answer for written or verbally administered items and entered answers on an electronic tablet. Item responses for each individual were combined into a summary score (range 0-17) with higher scores indicating better oral health literacy. Score dimensionality, reliability, and validity were investigated.

Results

For dimensionality, both exploratory factor analysis and a parallel analysis yielded evidence for scale unidimensionality. Reliability was sufficient indicated by a Cronbach's alpha ⟩0.74. Validity of scores was supported by "small" and "medium" effect sizes for construct validity. "Small" effect sizes were observed for global oral health self-report, OHIP-5 scores, treatment urgency, and having a regular dentist. "Medium" effect sizes were seen for presence of dentures, number of natural teeth present, and educational level.

Conclusions

Dimensionality, reliability and validity of the English version of the OHL-AQ in a general adult English-speaking population is supported, providing sufficient psychometric properties in an important target population of the instrument.

A Finite Mixture of Nonlinear Random Coefficient Models for Continuous Repeated Measures Data

Nonlinear random coefficient models (NRCMs) for continuous longitudinal data are often used for examining individual behaviors that display nonlinear patterns of development (or growth) over time in measured variables. As an extension of this model, this study considers the finite mixture of NRCMs that combine features of NRCMs with the idea of finite mixture (or latent class) models. The efficacy of this model is that it allows the integration of intrinsically nonlinear functions where the data come from a mixture of two or more unobserved subpopulations, thus allowing the simultaneous investigation of intra-individual (within-person) variability, inter-individual (between-person) variability, and subpopulation heterogeneity. Effectiveness of this model to work under real data analytic conditions was examined by executing a Monte Carlo simulation study. The simulation study was carried out using an R routine specifically developed for the purpose of this study. The R routine used maximum likelihood with the expectation-maximization algorithm. The design of the study mimicked the output obtained from running a two-class mixture model on task completion data.