Polychoric Correlations Research Articles

Association of intracluster correlation measures with outcome prevalence for binary outcomes in cluster randomised trials.

In cluster randomised trials, a measure of intracluster correlation such as the intraclass correlation coefficient (ICC) should be reported for each primary outcome. Providing intracluster correlation estimates may help in calculating sample size of future cluster randomised trials and also in interpreting the results of the trial from which they are derived. For a binary outcome, the ICC is known to be associated with its prevalence, which raises at least two issues. First, it questions the use of ICC estimates obtained on a binary outcome in a trial for sample size calculations in a subsequent trial in which the same binary outcome is expected to have a different prevalence. Second, it challenges the interpretation of ICC estimates because they do not solely depend on clustering level. Other intracluster correlation measures proposed for clustered binary data settings include the variance partition coefficient, the median odds ratio and the tetrachoric correlation coefficient. Under certain assumptions, the theoretical maximum possible value for an ICC associated with a binary outcome can be derived, and we proposed the relative deviation of an ICC estimate to this maximum value as another measure of the intracluster correlation. We conducted a simulation study to explore the dependence of these intracluster correlation measures on outcome prevalence and found that all are associated with prevalence. Even if all depend on prevalence, the tetrachoric correlation coefficient computed with Kirk's approach was less dependent on the outcome prevalence than the other measures when the intracluster correlation was about 0.05. We also observed that for lower values, such as 0.01, the analysis of variance estimator of the ICC is preferred.

PolychoricRM: A computationally efficient R function for estimating polychoric correlations and their asymptotic covariance matrix

ABSTRACT Many applications of structural equation modeling involve ordinal (e.g., Likert) variables. A popular way of dealing with ordinal variables is to estimate the model with polychoric correlations rather than Pearson correlations. Such an estimation also requires the asymptotic covariance matrix of polychoric correlations. It is computationally intensive to estimate polychoric correlations and their asymptotic covariance matrices. We describe a computationally efficient R function PolychoricRM to estimate polychoric correlations and their asymptotic covariance matrix. The function invokes the computing power of modern Fortran and exploits multiple-core (multiple-thread) CPUs on nearly all current computers.

The Conformist Attitudes Scale (SPK-II). Latent Structure Analysis Using the Bi-Factor Model

The aim of this article is to present the evaluation of psychometric properties of an original tool for measuring the propensity to adopt conformist attitudes in adolescents - the Conformist Attitudes Scale (SPK-II). The objective was achieved based on the results of exploratory (EFA) and confirmatory (CFA) factor analysis using a bi-factor model. Analyses were performed on a polychoric correlation matrix using the WLSMV estimator. The Geomin oblique rotation was used for the EFA. Data for the validation study were collected in Poland in 2012 and 2020 from 256 and 245 students aged 16-19, respectively. Of the solutions tested, the bi-factor model proved to be the best fit to the data (RMSEA= 0.052; CFI = 0.964; TLI = 0.953). Based on the Cronbach’s alpha coefficient, coefficients omega (ω), and ECV, the scale was found to have high reliability. At the same time, the stability of the scale’s latent structure, its dimensionality and reliability were positively verified by comparing the estimates for the data from 2012 and 2020. The analyses conducted allowed the researchers to assume that the SPK-II latent factor structure model consists of a general factor and three subfactors. The subfactors correspond to subscales which measure specified attributes of a general propensity to adopt conformist attitudes: lack of self-confidence, submissiveness to others and passivity in expressing one’s own views.The SPK-II fills a gap consisting in the absence of standardized research tools whose diagnostic spectrum is concerned with measuring the general propensity to adopt conformist attitudes in adolescents, taking into account attributes around which the conformity is focused. Its application enables studying conformity as an important adaptation mechanism in adolescence and predicting individual behaviour in various social situations related to participation in peer groups.

Familial aggregation and heritability: a nationwide family-based study of idiopathic inflammatory myopathies

ObjectivesThe magnitude of the genetic contribution to idiopathic inflammatory myopathies (IIMs) is unknown. In this project, we aimed to investigate the familial aggregation and heritability of IIM.MethodsThis is a family-based...

A cross-country comparison of malaria policy as a premise for contextualized appropriation of foreign aid in global health

BackgroundForeign aid continues to play an essential role in health sector development in low-resource countries, particularly in terms of providing a vital portion of their health expenditures. However, the relationship between foreign aid allocation and malaria policy formulation and/or implementation among state aid recipients remains unknown.MethodsPublicly available data were collected with the country as observational unit to set up the conceptual framework. The quality and strength of relationships between socioeconomic, environmental and institutional parameters were estimated by Pearson and polychoric correlations. A correlation matrix was explored by factor analysis.ResultsThe first policy index captured policy variation related to malaria burden and development assistance. Funding per capita from all international agencies was correlated with malaria burden, whereas governmental funding for national malaria programmes per capita was not. The second policy index captured variation beyond malaria endemicity and country size. Variation was found to be related to international country risk instruments and funding from the United States Agency for International Development President’s Malaria Initiative.ConclusionsNot all agencies involved in malaria policy allocate assistance in alignment with the gross domestic product and malaria burden. While the country size does not negatively impact malaria burden, it does account for greater development assistance per capita from selected international agencies. Novel policy indexes describe complex relationships between malaria policy, international foreign aid and socioeconomic parameters. Small countries have distinct environmental and sociopolitical properties.

Explaining Conspiracy Beliefs and Scepticism around the COVID-19 Pandemic.

Public opinion on COVID‐19 provides new empirical evidence for the debate on the ideological contours of conspiracy theories. I report findings from a web survey in Greece where participants were recruited via paid advertising on Facebook and the study sample was adjusted for age, gender, education, domicile, and region of residence using a nationally representative reference sample. I find that beliefs about conspiracy theories are more correlated than the values associated with established political ideologies, and that conspiracy beliefs and scepticism about the pandemic are best explained by belief in unrelated political and medical conspiracy theories. No other demographic or attitudinal variable has such a strong influence, and the results are robust to different statistical specifications. In comparison, the effect of ideology measured by left‐right self‐placement is rather negligible and further moderated by trust in government. The results have implications for the strategies aimed at fighting disinformation during public health emergencies.

Reliability and Dimensionality of EPREVO ("Experiencias de Parto Relacionadas a Violencia Obstétrica"): Development of a New Instrument, Ecuador.

BackgroundA new instrument called EPREVO has been developed to measure obstetric violence in Ecuador and the objective of this work is to validate its reliability and structural dimensionality.MethodsUsing confirmatory factor analysis (CFA) with a tetrachoric correlation approach. We examined the factor structure of EPREVO, a Spanish instrument to measure obstetric violence. Kuder Richardson values were used to assess the internal consistency of the scale and dimensionality was confirmed with confirmatory factor analysis.ResultsConfirmatory factor analysis supported a 3-factor solution. Most item-to-factor-correlations presented moderate to strong magnitude. Total Kuder Richardson was 0.87, while for the three factors were 0.23, 0.47 and 0.94, respectively. The model’s goodness-of-fit indexes were satisfactory (χ2 = 1458.83; χ2/g.l = 2.60, p < 0.001; NNFI = 0.90; RMSEA = 0.09); most of the factor loads were greater than 0.30. A confirmatory factor analysis suggested a 3-dimensional structure of EPREVO.ConclusionThe scale’s factor structure presented satisfactory validity and reliability results, except for one factor. The 30 items scale could potentially be used as an instrument for assessing obstetric violence in different healthcare settings.

Abstract P047: US Asian Indians Dying With Atherosclerosis Are More Likely To Have Concurrent Diabetes Mellitus

Background: Asian Indians (AI) in the US are known to have a high prevalence of atherosclerotic diseases and diabetes mellitus (DM). However, it is not known if these two cluster as causes of death in AI compared to the rest of US population. Methods: Using 2017 Multiple Cause-of-Death Data from the National Centre for Health Statistics, we included deaths at age ≥ 45 years among US residents where AI vs not-AI could be ascertained (n = 7940 AI; n = 2.6 million not-AI). DM (ICD-10 range: E10-E14) and any atherosclerosis (either of: ischemic heart disease, ischemic stroke, atherosclerosis; ICD-10 range: I20-I25, I69, I70, respectively) as contributing causes of death were identified in AI and not-AI. We calculated dichotomous tetrachoric correlation (Rho) between DM and atherosclerosis as co-occurring contributing causes. To examine whether this association differed by age decade and sex, we calculated the difference in fraction of deaths with DM in those with atherosclerosis versus those without atherosclerosis as a co-occurring cause of death. Results: There were 114,210 atherosclerosis deaths and 24,331 DM deaths in 2017 in the sample. DM and atherosclerosis as contributing causes correlated more strongly in AI (Rho = 0.36, p &lt; 0.001) as compared to not-AI (Rho = 0.31, p &lt; 0.001; difference between groups, p &lt; 0.001). The excess fraction of deaths due to DM when atherosclerosis also contributed vs when atherosclerosis did not contribute was higher in AI men of all ages and in most ages for AI women, except for a group where AI death numbers were smaller (Figure). Conclusion: Our findings highlight the increased burden of co-occurring DM and atherosclerotic disease together contributing as causes of death in AI compared to not-AI in the US. Public health strategies targeted to AI should focus on prevention and clinical treatment of both conditions jointly, in both men and women, especially during young adulthood and middle age.

Development and validation of the Cancer Knowledge Scale for the general population: An item response theory approach

ObjectiveTo develop and validate a new measure of cancer knowledge for members of the general population who have never been diagnosed with cancer. MethodsInitially, 20 items were generated to measure cancer knowledge. After expert refinement and cognitive interviews, 11 items remained and were completed by 1,076 adults with no history of cancer. Responses were assessed using an item response theory (IRT) approach and differential item functioning. ResultsItems were analyzed using a two-parameter logistic IRT model. Two items with tetrachoric correlation coefficients>0.8 and one item with a discrimination parameter>2.0 were excluded. The final eight items demonstrated a good range of discrimination (1.13 to 1.86) and difficulty (−1.11 to 0.85). No meaningful differential item functioning by participant attributes was detected for these eight items. ConclusionThe Cancer Knowledge Scale appears to be a reliable and valid measure for the general population. Practice ImplicationsThe eight-item scale could be used to assess the effects of psychoeducational programs, including those on cancer knowledge, for members of the general population with no cancer history

Psychometric properties of the Child Eating Behavior Questionnaire (CEBQ) in school age children with overweight and obesity: A proposed three-factor structure.

Obesity in youth is a significant public health concern, with eating behaviors being a major contributor. The Child Eating Behavior Questionnaire (CEBQ) was developed to evaluate the appetitive characteristics of young children, across a myriad of eating domains. Despite the breadth of its use, the psychometric properties of the measure in children with overweight/obesity (OW/OB), particularly treatment seeking youth, remains largely unexplored. The psychometric properties of the CEBQ were examined in a sample of school age children (8-12) with OW/OB. Parent-child dyads (N=148) completed assessments prior to beginning a family weight management program. Exploratory factor analysis (EFA) was performed utilizing polychoric correlations, and emerging subscales were assessed to ensure that the range of response scores demonstrated adequate variability. Indices of the number of factors to be retained included acceleration factor (2), optimal coordinates (4), Velicer's MAP (5) and parallel analysis (11). These indices were used in combination with clinical utility to determine the final factor structure. A three-factor structure emerged. The first factor combined many food responsiveness, enjoyment of food, satiety responsiveness and slowness in eating items, with the latter two domains loading negatively. The second factor retained the food fussiness subscale, and the third factor included items from the emotional over- and under-eating subscales. These results suggest that in children with OW/OB, eating behaviors may be optimally assessed using three domains: reward-based eating, emotional eating and picky eating. Future research should explore how this structure holds in non-treatment-seeking samples and across wider socio-demographic profiles.

Validation of the Arabic version of the Teruel Orthorexia Scale (TOS) among Lebanese adolescents.

ObjectivesThis study aimed at examining the reliability and validity of the Teruel Orthorexia Scale (TOS) among a sample of Lebanese adolescents (15 to 18 years old).MethodsThis is a cross-sectional study that was conducted between May and June 2020 and had enrolled 555 Lebanese adolescents. To assess the internal structure of the TOS scale, we administered the confirmatory factor analysis based on polychoric correlation matrix using Weighted Least Squares with Means and Variance Adjusted estimation (WLSMV) method in Mplus v 7.2 as suggested in the original validation paper. To assess the degree to which the Lebanese adaptation converges with the original scale, we have conducted the Multigroup Confirmatory Factor Analysis (MGCFA; estimated as CFA) between the data reported in the current paper and from the original validation paper.ResultsThe mean age of the participants was 16.66 ± 1.01 years, with 76.1% females. The bi-dimensional model fitted the data well (χ2(118) = 429.09; p < 0.001; CFI = 0.954; RMSEA = 0.069[0.062, 0.076]). The latent factors were highly correlated (ρ = 0.74; p < 0.001), and the strength of the standardized factor loadings was adequate on both factors (i.e., all > 0.60). The fit indices of the scalar model were at the boundary of the threshold and thus, with some pinch of caution, it might be interpreted as invariant (i.e., having equal item intercepts across groups). We have identified latent mean differences in orthorexia nervosa (0.30; p < 0.001), where Spanish individuals scored higher, but we did not find any differences in the healthy eating (0.03; p = 0.636).Higher DOS scores were significantly correlated with higher scores on the TOS subscale OrNe (r = 0.715; p < 0.001) as well as with higher scores on the TOS subscale HeOR (r = 0.754; p < 0.001). Higher ORTO-R scores were significantly associated with less TOS OrNe (r = − 0.437; p < 0.001) and TOS HeOr (r = − 0.305; p < 0.001) scores, respectively.ConclusionThe Arabic version of the TOS can be considered a reliable valuable instrument to assess the ON tendencies and behaviors in Lebanese adolescents, emphasizing the fine contrast between ON’s two dimensions: healthy vs. pathological.Level VOpinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Principal Component Analysis of Munich Functional Developmental Diagnosis.

Objectives: Munich Functional Developmental Diagnosis (MFDD) is a scale for assessing the psychomotor development of children in the first months or years of life. The tool is based on standardized tables of physical development and is used to detect developmental deficits. It consists of eight axes on which the following skills are assessed: crawling, sitting, walking, grasping, perception, speaking, speech understanding, social skills. Methods: The study included 110 children in the first year of life examined with the MFDD by the same physician. The score obtained on a given axis was coded as a negative value (defined in months) below the child’s age-specific developmental level. Next, we examined the dimensionality of the scale and the intercorrelation of its axes using polychoric correlation and principal component analysis. Results: Correlation matrix analysis showed high correlation of MFDD axes 1–4, and MFDD 6–8. The PCA identified three principal components consisting of children’s development in the areas of large and small motor skills (axis 1–4), perception (axis 5), active speech, passive speech and social skills (axis 6–8). The three dimensions obtained together account for 80.27% of the total variance. Conclusions: MFDD is a three-dimensional scale that includes motor development, perception, and social skills and speech. There is potential space for reduction in the number of variables in the scale.

CORRELATION STRUCTURE OF THE COORDINATION PREPAREDNESS OF MALE ADOLESCENTS AGED 13–14 ENGAGED IN EXTREME ACTIVITY

Analysis of scientific works shows that in recent years, extreme sports have developed very rapidly, and scientists have interested in extreme personality phenomenon, in particular, trying to find out what drives people who engage in extreme motor activity types. The aim of the study was to identify the presence of correlations between indicators of coordination qualities and of basic mental properties and processes in adolescents aged 13-14 years, who are engaged in extreme motor activity (MA) types. Materials and methods. The study involved male adolescents aged 13–14 years (n = 47) who are involved in extreme MA types. The tetrachoric correlation coefficient and the Chuprov correlation coefficient were used to determine the correlations between mental and physical components indicators, and the parametric Brave-Pearson correlation coefficient was used to establish the relations between coordination qualities indicators. Statistical processing was performed using the application package Statistics 6.0. Results. The study of coordination abilities structure of the studied contingent revealed that ability indicators to manage spatio-temporal characteristics are related to locus control indicators (0.44), alertness (-0.34), mechanical (-0.34) and logical (-0.32) memory; the ability to spatial parameters differentiation correlates with anxiety (0.64), locus control (-0.62), alertness (0.35) and mechanical memory (-0.31); the ability to differentiate temporal parameters correlates with mental properties indicators (anxiety, stress and locus control), as well as mental processes indicators: mechanical memory (-0.47) and alertness (-0.38); proneness to stress indicator (-0.32) correlates with the ability to maintain static balance; logical memory indicator (-0.51), proneness to stress (0.35), locus control (0.37) and mechanical memory (-0.37) correlates with the ability to maintain dynamic balance; indicators of social desirability bias (0.49), mechanical memory (0.35) and locus control (-0.32) correlated with the ability to general movements coordination. Conclusions. The integrated coordination abilities indicator is presented by leading and background indicators that influence and determine the coordination preparedness of adolescents aged 13–14 who are engaged in extreme MA.

Productivity metrics in the context of knowledge work: literature vs practice

PurposeThe purpose of this paper is to perform a comparative analysis between the productivity metrics recommended in the literature and those that companies in the knowledge-intensive services sector use in practice.Design/methodology/approachTo collect information, a systematic review of the literature was used, to apply virtual surveys and interviews among managers of different companies representing the sector. For data analysis, categorical optimal scales, homogeneity tests, tetrachoric correlation matrices, word clouds and association coefficients for dichotomous variables were used.FindingsThere are association patterns between the metrics used and the nature of the work performed. Despite the heterogeneity observed in the productivity metrics, categorization guidelines related to the traditional, human resources and customer-oriented approaches emerge.Practical implicationsPossible neglects using metrics aimed at valuing the intellectual capital immersed in human resources are evident, particularly in the follow-up to autonomy, knowledge management, human capital, teamwork, training and capacity building metrics, among others. Conversely, face-to-face monitoring metrics, such as absenteeism, are overvaluation.Originality/valueThe approaches and metrics discussed and the results obtained, provide information so that knowledge-intensive companies have a reference framework to identify and select useful metrics to assess the work carried out by their workforce.

Adoption of Green Environmental Practices in Small and Medium-Sized Enterprises: Entrepreneur and Business Policies Patterns in Romania

Current research shows that SMEs’ social and environmental actions are fragmented and informal, and few have formal policies and intentions. At the same time, many SMEs are engaged with environmental policies, often not knowing it. Concurrently, there is a gap between the pro-environmental attitudes of the SMEs managers, who are often seen as the main drivers for the firm’s behavior, and the policies implemented in reality in their firms. To this end, our research’s objective is to explore pro-environmental behavior, both at the individual and firm level, to identify connections between these levels and measures but also with firm’s and managers’ demographics, based on a study of Romanian SMEs. The descriptive analysis and factor analysis including tetrachoric correlation methods were used to explore these behaviors and the associations between them. The results confirm the research’s hypothesis and show that there are positive connections between the “green” behaviors at the individual level and in the SME context. Moreover, comparative analysis provided evidence of differences in the adoption of environmental practices, which were based on the firm’s demographics and manager’s characteristics. Simultaneously, five typologies of pro-environmental behavior in SMEs were identified and described, depending on the additional investment necessary and allocated resources, on the changes in organizational structure, and on the manager’s personal involvement. These findings contribute to a better understanding of the environmental improvement policies in SMEs and may help policy-makers tailor interventions and SMEs managers learn from good practices of their peers.

Changes in Multimorbidity and Polypharmacy Patterns in Young and Adult Population over a 4-Year Period: A 2011-2015 Comparison Using Real-World Data.

The pressing problem of multimorbidity and polypharmacy is aggravated by the lack of specific care models for this population. We aimed to investigate the evolution of multimorbidity and polypharmacy patterns in a given population over a 4-year period (2011–2015). A cross-sectional, observational study among the EpiChron Cohort, including anonymized demographic, clinical and drug dispensation information of all users of the public health system ≥65 years in Aragon (Spain), was performed. An exploratory factor analysis, stratified by age and sex, using an open cohort was carried out based on the tetra-choric correlations among chronic diseases and dispensed drugs during 2011 and compared with 2015. Seven baseline patterns were identified during 2011 named as: mental health, respiratory, allergic, mechanical pain, cardiometabolic, osteometabolic, and allergic/derma. Of the epidemiological patterns identified in 2015, six were already present in 2011 but a new allergic/derma one appeared. Patterns identified in 2011 were more complex in terms of both disease and drugs. Results confirmed the existing association between age and clinical complexity. The systematic associations between diseases and drugs remain similar regarding their clinical nature over time, helping in early identification of potential interactions in multimorbid patients with a high risk of negative health outcomes due to polypharmacy.

The Development of Preliminary HiTOP Internalizing Spectrum Scales.

As part of a broader project to create a comprehensive self-report measure for the Hierarchical Taxonomy of Psychopathology consortium, we developed preliminary scales to assess internalizing symptoms. The item pool was created in four steps: (a) clarifying the range of content to be assessed, (b) identifying target constructs to guide item writing, (c) developing formal definitions for each construct, and (d) writing multiple items for each construct. This yielded 430 items assessing 57 target constructs. Responses from a heterogeneous scale development sample (N = 1,870) were subjected to item-level factor analyses based on polychoric correlations. This resulted in 39 scales representing a total of 213 items. The psychometric properties of these scales replicated well across the development sample and an independent validation sample (N = 496 adults). Internal consistency analyses established that most scales assess relatively narrow forms of psychopathology. Structural analyses demonstrated the presence of a strong general factor. Additional analyses of the 35 nonsexual dysfunction scales revealed a replicable four-factor structure with dimensions we labeled Distress, Fear, Body Dysmorphia, and Mania. A final set of analyses established that the internalizing scales varied widely-and consistently-in the strength of their associations with neuroticism and extraversion.

Auto-assignment of providers in Medicaid Managed Care and factors influencing seasonal flu vaccine uptake: a retrospective analysis

ObjectivesOver 50 million people in the USA are enrolled in a Medicaid Managed Care plan. If they do not select a primary care provider, they are auto-assigned to one. The impact of auto-assignment has largely been understudied outside the context of patient satisfaction with the insurance plan. The purpose of the study was to explore the association between auto-assignment and flu vaccination use, which will contribute to our understanding of factors influencing the COVID-19 vaccine uptake.MethodsRetrospective data from the Enterprise Data Warehouse of a health system were obtained for adult Medicaid enrolees assigned to a Midwestern health system in 2019. Descriptive statistics, independent t-tests and tetrachoric correlations were used to explore the relationship between auto-assignment and flu vaccine receipt among a large sample of Illinois residents (N = 7224). The sample was then divided into those who chose their provider (n = 6027) and those who were auto-assigned (n = 1197).Key findingsIndividuals who selected their provider were deemed to have flu vaccine coverage over those who were auto-assigned (33.2% vs. 6.6%). Furthermore, among those who were auto-assigned, age, number of office visits and having chronic morbidities, including chronic obstructive pulmonary disease (P < 0.01), diabetes (P < 0.01) and heart failure (P < 0.01), were positively associated with flu vaccine receipt.ConclusionsIndividuals who are auto-assigned to a primary care provider are less likely to be flu vaccine recipients than those who choose their provider. This suggests that auto-assignment is a risk factor that influences vaccine receipt. This research provides perspectives for outreach efforts that target individuals who are auto-assigned to a provider.

The Structure of the Prodromal Questionnaire-16 (PQ-16): Exploratory and confirmatory factor analyses in a general non-help-seeking population sample.

To examine the structure of the Prodromal Questionnaire (PQ-16) in a non-help-seeking population through exploratory factor analysis and confirmatory factor analysis. Previous studies have not looked at the structure of this self-report measure outside clinical settings. Participants (n = 1045) were recruited through Amazon's Mechanical Turk (MTurk), and then completed the PQ-16. The data set was split randomly in two, one being used for exploratory factor analysis (EFA) and the other for confirmatory factor analysis (CFA). A polychoric correlation matrix was created and EFA was used to explore the factor structure of the PQ-16. Four models were tested through CFA to determine best fit: one, two, three and four-factor models were all analysed. EFA indicated a two-factor structure in the PQ-16 in a non-help-seeking population (with a mean age = 29.7 years). Factor 1 represented perceptual abnormalities/hallucinations and factor 2 general symptoms associated with psychosis-risk. CFA indicated that all the proposed models were suitable fits for the dataset. Fit indices for the three-factor model (factor 1 representing perceptual abnormalities/hallucinations, factor 2 unusual thought content, and factor 3 negative symptom) indicated that it appeared to be a better fit for the data than the one, two, and four factor models. This study suggests that a three-factor model of the PQ-16 is a better fit than other proposed models in a non-help-seeking population. Future research of the structure of the PQ-16 in this population may benefit from recruiting subjects with a lower mean age than the current study.

Examining the frequency of crenulated premolars and their association with crenulated molars.

Crenulated occlusal surfaces have previously been described on maxillary and mandibular molars; however, the occurrence of crenulations on premolars is only anecdotally supported. This study applies a modified version of a recordation scale developed for molar crenulations to record the frequency of crenulated premolars on the maxillary and mandibular premolars of modern individuals from a variety of populations: African, African American, Asian, Australian, European American, Latino, and Malay (n = 1238). Crenulations on the molars of the same individuals were also recorded to assess the relationship between occurrences on premolars and molars. Observations were compiled into frequency tables and analyzed using chi-square tests and correspondence analysis; relationships among teeth were quantified with polychoric correlation coefficients. Although crenulated premolars are observed rarely overall, the frequency of occurrence is significantly associated with group membership. Crenulated premolars occur most frequently in African, African American, and Australian samples and are observed least often among European American and Malay samples. Additionally, there is a strong relationship between third and fourth premolars, particularly within a jaw, and between fourth premolars and the molars in the same jaw. Interestingly, crenulations in premolars are most strongly associated with Grade 2 crenulations on molars. The observed differences between populations, and the associations between crenulated premolars and molars are evaluated with respect to function, tooth size, and dental development. Based on the results presented here, we recommend the addition of premolar crenulations to existing dental morphological traits used to study human population variation.