A qualitative analysis of pressure injury development among medically underserved adults with spinal cord injury.

Purpose: Medically underserved adults with spinal cord injury (SCI) remain at high risk of incurring medically serious pressure injuries even after receiving education in prevention techniques. The purpose of this research is to identify circumstances leading to medically serious pressure injury development in medically underserved adults with SCI during a lifestyle-based pressure injury prevention program, and provide recommendations for future rehabilitation approaches and intervention design.Methods: This study entailed a qualitative secondary case analysis of treatment notes from a randomized controlled trial. Participants were 25 community-dwelling, medically underserved adults with SCI who developed medically serious pressure injuries during the course of the intervention of the RCT.Results and conclusions: Among the 25 participants, 40 unique medically serious pressure injuries were detected. The six themes related to medically serious pressure injury development were: (1) lack of rudimentary knowledge pertaining to wound care; (2) equipment and supply issues; (3) comorbidities; (4) non-adherence to prescribed bed rest; (5) inactivity; and (6) circumstances beyond the intervention's reach. Together, these factors may have undermined the effectiveness of the intervention program. Modifications, such as assessing health literacy levels of patients prior to providing care, providing tailored wound care education, and focusing on equipment needs, have potential for altering future rehabilitation programs and improving health outcomes.Implications for rehabilitationTo provide patients with spinal cord injury with the necessary information to prevent medically serious pressure injury development, health care providers need to understand their patient's unique personal contexts, including socio-economic status, language skills, and mental/cognitive functioning.When providing wound care information to patients with spinal cord injury who have developed a medically serious pressure injury, practitioners should take into account the level of health literacy of their patient in order to provide education that is appropriate and understandable.Practitioners should be aware of how to help their patient advocate for outside services and care that address their equipment needs, such as finding funding or grants to pay for expensive medical equipment.

Factors Protecting Against Pressure Injuries in Medically Underserved Adults With Spinal Cord Injury: A Qualitative Study.

Background: Pressure injuries negatively impact quality of life and participation for individuals with spinal cord injury (SCI). Objective: To examine the factors that may protect against the development of medically serious pressure injuries in adults with SCI. Methods: A qualitative analysis was conducted using treatment notes regarding 50 socioeconomically disadvantaged individuals who did not develop medically serious pressure injuries during a 12-month pressure injury prevention intervention program. Results: Eight types of potentially protective factors were identified: meaningful activity, motivation to prevent negative health outcomes, stability/resources, equipment, communication and self-advocacy skills, personal traits, physical factors, and behaviors/activities. Conclusions: Some protective factors (eg, personal traits) may be inherent to certain individuals and nonmodifiable. However, future interventions for this population may benefit from a focus on acquisition of medical equipment and facilitation of sustainable, health-promoting habits and routines. Substantive policy changes may be necessary to facilitate access to adequate resources, particularly housing and equipment, for socioeconomically disadvantaged individuals with SCI. Further research is needed to understand the complex interplay of risk and protective factors for pressure injuries in adults with SCI, particularly in underserved groups.

The association of health-related quality of life with unmet supportive care needs and sociodemographic factors in low-income Latina breast cancer survivors: a single-centre pilot study.

Purpose: Determine correlations between health-related quality of life (HRQOL), supportive care need, and sociodemographic factors in low-income Latina breast cancer survivors.Methods: A descriptive, survey-based, cross-sectional study was completed with 102 low-income Latina breast cancer survivors at a major public safety net hospital. Correlation coefficients were calculated between number of unmet supportive care needs (per Supportive Care Needs Survey), HRQOL (per SF-36), and sociodemographic variables.Results: Unmet supportive care needs were correlated with lower HRQOL in all domains (r > -0.40; p < 0.0001). Lower income was significantly associated with lower HRQOL (r > 0.21; p < 0.05) and more supportive care needs (r = -0.22; p < 0.05). Multimorbidity was significantly associated with decreased HRQOL (r > -0.23; p < 0.05) and greater supportive care need (r = 0.19; p < 0.05).Conclusions: Identifying and addressing unmet supportive care needs may improve HRQOL in low-income Latina breast cancer survivors. Rehabilitation interventions that address barriers to accessing supportive care related to low SES and multimorbidity may also improve health outcomes in this population. The dual effect of multimorbidity on both quality of life and level of supportive care need in this population warrants further investigation.Implications for rehabilitationScreening for unmet supportive care needs may be an important step in improving health-related quality of life during cancer rehabilitation.Challenges accompanying multimorbidity and lower socioeconomic status may prevent low-income cancer patients from accessing adequate supportive care.Rehabilitation interventions for socioeconomically disadvantaged cancer survivors should compensate for both socioeconomic status and the presence of comorbidities in order to reduce disparities in quality of life during survivorship.

Lifestyle intervention for adults with spinal cord injury: Results of the USC-RLANRC Pressure Ulcer Prevention Study.

CONTEXT/OBJECTIVE: Medically serious pressure injuries (MSPrIs), a common complication of spinal cord injury (SCI), have devastating consequences on health and well-being and are extremely expensive to treat. We aimed to test the efficacy of a lifestyle-based intervention designed to reduce incidence of MSPrIs in adults with SCI. DESIGN: A randomized controlled trial (RCT), and a separate study wing involving a nonrandomized standard care control group. SETTING: Rancho Los Amigos National Rehabilitation Center, a large facility serving ethnically diverse, low income residents of Los Angeles County. PARTICIPANTS: Adults with SCI, with history of one or more MSPrIs over the past 5 years: N=166 for RCT component, N=66 in nonrandomized control group. INTERVENTIONS: The Pressure Ulcer Prevention Program, a 12-month lifestyle-based treatment administered by healthcare professionals, largely via in-home visits and phone contacts. OUTCOME MEASURES: Blinded assessments of annualized MSPrI incidence rates at 12 and 24 months, based on: skin checks, quarterly phone interviews with participants, and review of medical charts and billing records. Secondary outcomes included number of surgeries and various quality-of-life measures. RESULTS: Annualized MSPrI rates did not differ significantly between study groups. At 12 months, rates were .56 for intervention recipients, .48 for randomized controls, and .65 for nonrandomized controls. At follow-up, rates were .44 and .39 respectively for randomized intervention and control participants. CONCLUSIONS: Evidence for intervention efficacy was inconclusive. The intractable nature of MSPrI threat in high-risk SCI populations, and lack of statistical power, may have contributed to this inability to detect an effect. TRIAL REGISTRATION: ClinicalTrials.gov NCT01999816.

Supportive care priorities of low-income Latina breast cancer survivors.

PURPOSE: This study investigated the supportive care needs of a sample of low-income Latina breast cancer survivors. METHODS: Ninety-nine Spanish-speaking breast cancer survivors who self-identified as Latina and reported an income below the US Census Bureau low-income threshold were recruited from the oncology clinic of a major public safety net hospital. Eligible participants completed the supportive care needs survey (SCNS-SF34) and a demographic questionnaire. RESULTS: Ninety-three percent of respondents had unmet needs. The majority of frequently reported unmet needs involved (1) access to and delivery of health-related information and (2) physical function. These findings appear to contrast with those of other studies of supportive care needs in heterogeneous cancer survivors, most of which describe psychological concerns as most urgent. CONCLUSIONS: Participants espoused information-related needs with a higher frequency than many other samples of cancer survivors. This study population may also require a particularly high level of assistance with overcoming participation restrictions. Further research is needed to understand these discrepancies and to address unmet needs across all domains.

Understanding the Mechanisms of Change in a Lifestyle Intervention for Older Adults.

Purpose of the Study: This study investigated the mechanisms of change underlying an activity-based lifestyle intervention, an occupational therapy program aimed at promoting healthy habits, and routines in older adults. We examined two activity-relevant factors as potential mediators linking the intervention to reduced symptoms of depression: activity frequency and global perceptions of activity significance. Social connections and perceived control were assessed to understand how activity-related factors relate to reduced symptoms of depression. Design and Methods: The sample consisted of 460 multiethnic community-dwelling older adults aged 60-95 years. Participants were randomly assigned to a 6-month lifestyle redesign intervention (n = 232) or a no-treatment control (n = 228) condition. After the 6-month period, 360 individuals completed post-testing. Latent change score models were used to represent changes from baseline over the experimental interval. Structural equation models were applied to examine the indirect effects of the intervention on reduced depressive symptoms. Results: The results demonstrated significant indirect effects from intervention receipt to decreased depressive symptoms via increased activity frequency and activity significance. Higher activity frequency was linked to fewer depressive symptoms via heightened social connections, whereas increased activity significance was associated with fewer depressive symptoms via enhanced perceived control. Implications: The results support basic principles of occupational therapy by highlighting important mediating roles of activity frequency and activity significance in reducing depressive symptoms. Understanding of these change mechanisms can help optimize activity-centered interventions to reduce depressive symptoms.

Promoting Translational Research Among Movement Science, Occupational Science, and Occupational Therapy.

Integration of research in the fields of neural control of movement and biomechanics (collectively referred to as movement science) with the field of human occupation directly benefits both areas of study. Specifically, incorporating many of the quantitative scientific methods and analyses employed in movement science can help accelerate the development of rehabilitation-relevant research in occupational therapy (OT) and occupational science (OS). Reciprocally, OT and OS, which focus on the performance of everyday activities (occupations) to promote health and well-being, provide theoretical frameworks to guide research on the performance of actions in the context of social, psychological, and environmental factors. Given both fields' mutual interest in the study of movement as it relates to health and disease, the authors posit that combining OS and OT theories and principles with the theories and methods in movement science may lead to new, impactful, and clinically relevant knowledge. The first step is to ensure that individuals with OS or OT backgrounds are academically prepared to pursue advanced study in movement science. In this article, the authors propose 2 strategies to address this need.

Qualitative Experience of Sleep in Individuals With Spinal Cord Injury.

Poor sleep contributes to adverse health outcomes making it important to understand sleep in medically vulnerable populations, including those with spinal cord injury (SCI). However, little attention has been paid to circumstances specific to SCI that may negatively affect sleep, or to consequences of poor sleep in this population. The objective of this study was to examine the experience of sleep among individuals with SCI. Secondary analysis using thematic coding of qualitative data from an ethnographic study of community-dwelling adults with SCI was conducted. Sleep-related data were found in transcripts for 90% of the sample. Participants described diminished sleep duration and irregular sleep patterns. Several factors contributing to poor sleep were identified, including SCI-related circumstances and sleep environment. Participants also discussed how poor sleep affected occupational engagement. This study highlights the extent of sleep disturbance experienced after SCI and the subsequent impact on occupational performance, and provides direction for clinical practice.

Systematic review of behavioral and educational interventions to prevent pressure ulcers in adults with spinal cord injury.

OBJECTIVE: To investigate the efficacy of behavioral or educational interventions in preventing pressure ulcers in community-dwelling adults with spinal cord injury (SCI). DATA SOURCES: Cochrane, Clinical Trials, PubMed, and Web of Science were searched in June 2016. The search combined related terms for pressure ulcers, spinal cord injury, and behavioral intervention. Each database was searched from its inception with no restrictions on year of publication. REVIEW METHODS: Inclusion criteria required that articles were (a) published in a peer-reviewed journal in English, (b) evaluated a behavioral or educational intervention for pressure ulcer prevention, (c) included community-dwelling adult participants aged 18 years and older with SCI, (d) measured pressure ulcer occurrence, recurrence, or skin breakdown as an outcome, and (e) had a minimum of 10 participants. All study designs were considered. Two reviewers independently screened titles and abstracts. Extracted information included study design, sample size, description of the intervention and control condition, pressure ulcer outcome measures, and corresponding results. RESULTS: The search strategy yielded 444 unique articles of which five met inclusion criteria. Three were randomized trials and two were quasi-experimental designs. A total of 513 participants were represented. The method of pressure ulcer or skin breakdown measurement varied widely among studies. Results on pressure ulcer outcomes were null in all studies. Considerable methodological problems with recruitment, intervention fidelity, and participant adherence were reported. CONCLUSIONS: At present, there is no positive evidence to support the efficacy of behavioral or educational interventions in preventing pressure ulcer occurrence in adults with SCI.

Napping and Nighttime Sleep: Findings From an Occupation-Based Intervention.

OBJECTIVE: To describe sleeping behaviors and trends over time among an ethnically diverse group of community-living older adults. METHOD: A descriptive secondary data analysis of a subsample (n = 217) from the Lifestyle Redesign randomized controlled trial was done to explore baseline napping and sleeping patterns as well as 6-mo changes in these outcomes. RESULTS: At baseline, the average time sleeping was 8.2 hr daily (standard deviation = 1.7). Among all participants, 29% reported daytime napping at baseline, of which 36% no longer napped at follow-up. Among participants who stopped napping, those who received an occupation-based intervention (n = 98) replaced napping time with nighttime sleep, and those not receiving an intervention (n = 119) experienced a net loss of total sleep (p < .05). CONCLUSION: Among participants who stopped napping, the occupation-based intervention may be related to enhanced sleep. More research examining the role of occupation-based interventions in improving sleep is warranted.

The role of habit in recurrent pressure ulcers following spinal cord injury.

BACKGROUND: Despite the existence of numerous prevention strategies, pressure ulcers remain highly prevalent in those with spinal cord injury (SCI). The concept of habit, broadly defined, may help understand the persistence of this problem and offer strategies for its mitigation by occupational therapy. AIM: The aim of this paper is to describe the relationship between habits established prior to sustaining an SCI and post-injury habits that impacted on pressure ulcer risk. METHODS: Secondary analysis of qualitative data collected during an ethnographic study of community-dwelling adults with SCI. RESULTS: Participants' habits appeared to substantially affect their risk of developing pressure ulcers. Habits established before incurring the SCI either facilitated or hindered the acquisition of new habits intended to prevent pressure ulcers. CONCLUSIONS: An understanding of the individual's pre-existing habits may be important when designing a rehabilitation programme intended to minimize risk of pressure ulcer development following SCI. Habit-change strategies could be used to supplement education in pressure ulcer prevention techniques. SIGNIFICANCE: Occupational therapists have a longstanding interest in habit. A more comprehensive understanding of this concept may provide important insights into the persistence and management of pressure ulcers following SCI.

Developing Occupation-Based Preventive Programs for Late-Middle-Aged Latino Patients in Safety-Net Health Systems.

Latino adults between ages 50 and 60 yr are at high risk for developing chronic conditions that can lead to early disability. We conducted a qualitative pilot study with 11 Latinos in this demographic group to develop a foundational schema for the design of health promotion programs that could be implemented by occupational therapy practitioners in primary care settings for this population. One-on-one interviews addressing routines and activities, health management, and health care utilization were conducted, audiotaped, and transcribed. Results of a content analysis of the qualitative data revealed the following six domains of most concern: Weight Management; Disease Management; Mental Health and Well-Being; Personal Finances; Family, Friends, and Community; and Stress Management. A typology of perceived health-actualizing strategies was derived for each domain. This schema can be used by occupational therapy practitioners to inform the development of health-promotion lifestyle interventions designed specifically for late-middle-aged Latinos.

Lifestyle changes and pressure ulcer prevention in adults with spinal cord injury in the pressure ulcer prevention study lifestyle intervention.

Pressure ulcers (PrUs) are a major burden to patients with spinal cord injury (SCI), affecting their psychological, physical, and social well-being. Lifestyle choices are thought to contribute to the risk of developing PrUs. This article focuses on the interaction between lifestyle choices and the development of PrUs in community settings among participants in the University of Southern California-Rancho Los Amigos National Rehabilitation Center Pressure Ulcer Prevention Study (PUPS II), a randomized controlled trial of a lifestyle intervention for adults with SCI. We conducted a secondary cross-case analysis of treatment notes of 47 PUPS II participants and identified four patterns relating PrU development to lifestyle changes: positive PrU changes (e.g., healing PrUs) with positive lifestyle changes, negative or no PrU changes with positive lifestyle changes, positive PrU changes with minor lifestyle changes, and negative or no PrU changes with no lifestyle changes. We present case studies exemplifying each pattern.

Development and validation of the activity significance personal evaluation (ASPEn) scale.

BACKGROUND/AIM: Engagement in desired occupations can promote health and wellbeing in older adults. Assessments of engagement often measure frequency, amount or importance of specific activities. This study aimed to develop a scale to measure older adults' evaluation of the extent to which their everyday activities are contributing to their health and wellness. METHODS: Eighteen items, each scored with a seven-point rating scale, were initially developed by content experts, covering perceptions of how daily activities contribute to physical and mental health, as well as satisfaction and activity participation in the last six months. Rasch analysis methods were used to refine the scale using the pencil and paper responses of 460 community-living older adults. RESULTS: Initial Rasch analysis indicated three unlabelled rating scale categories were seldom used, reducing measurement precision. Five items were conceptually different by misfit statistics and principal component analysis. Subsequently, those items were removed and the number of rating scale steps reduced to 4. The remaining 13-item, 4-step scale, termed the Activity Significance Personal Evaluation (ASPEn), formed a unidimensional hierarchy with good fit statistics and targeting. Person separation reliability (2.7) and internal consistency (.91) indicated the tool is appropriate for individual person measurement. Relative validity indicated equivalence between Rasch measures and total raw scores. CONCLUSIONS: ASPEn is a brief, easily administered assessment of older adults' perception of the contribution of everyday activities to personal health and wellness. ASPEn may facilitate occupational therapy practice by enabling clinicians to assess change in meaning of an older adult's activity over time.

Building a framework for implementing new interventions.

Implementation into real-world practice of interventions previously studied in randomized controlled trials is an ongoing challenge. In this article, we describe the methodology we used for the first phase of a project for the implementation and outcomes assessment of an occupational therapy pressure ulcer prevention intervention for people with spinal cord injury in the Veterans Health Administration. This first phase of the project was guided by practice-based evidence research methodology and resulted in an intervention manual tailored to meet the needs of Veterans and the establishment of a system for documenting and monitoring care processes, patient characteristics, and intervention outcomes. This system, in turn, will provide the data-gathering template for the next phase in which the beneficial effects of the intervention will be assessed. We conclude by recommending that clinicians explore the utility of this approach for the implementation of other novel interventions.

Implementing trials of complex interventions in community settings: the USC-Rancho Los Amigos pressure ulcer prevention study (PUPS).

BACKGROUND: Randomized trials of complex, non-pharmacologic interventions implemented in home and community settings, such as the University of Southern California (USC)-Rancho Los Amigos National Rehabilitation Center (RLANRC) Pressure Ulcer Prevention Study (PUPS), present unique challenges with respect to (1) participant recruitment and retention, (2) intervention delivery and fidelity, (3) randomization and assessment, and (4) potential inadvertent treatment effects. PURPOSE: We describe the methods employed to address the challenges confronted in implementing PUPS. In this randomized controlled trial, we are assessing the efficacy of a complex, preventive intervention in reducing the incidence of, and costs associated with, the development of medically serious pressure ulcers in people with spinal cord injury. METHODS: Individuals with spinal cord injury recruited from RLANRC were assigned to either a 12-month preventive intervention group or a standard care control group. The primary outcome is the incidence of serious pressure ulcers with secondary endpoints including ulcer-related surgeries, medical treatment costs, and quality of life. These outcomes are assessed at 12 and 24 months after randomization. Additionally, we are studying the mediating mechanisms that account for intervention outcomes. RESULTS: PUPS has been successfully implemented, including recruitment of the target sample size of 170 participants, assurance of the integrity of intervention protocol delivery with an average 90% treatment adherence rate, and enactment of the assessment plan. However, implementation has been replete with challenges. To meet recruitment goals, we instituted a five-pronged approach customized for an underserved, ethnically diverse population. In intervention delivery, we increased staff time to overcome economic and cultural barriers to retention and adherence. To ensure treatment fidelity and replicability, we monitored intervention protocol delivery in accordance with a rigorous plan. Finally, we have overcome unanticipated assessment and design concerns related to (1) determining pressure ulcer incidence/severity, (2) randomization imbalance, and (3) inadvertent potential control group contamination. LIMITATIONS: We have addressed the most daunting challenges encountered in the recruitment, assessment, and intervention phases of PUPS. Some challenges and solutions may not apply to trials conducted in other settings. CONCLUSIONS: Overcoming challenges has required a multifaceted approach incorporating individualization, flexibility, and persistence, as well as the ability to implement needed mid-course corrections.

Predictors of retention among African American and Hispanic older adult research participants in the Well Elderly 2 randomized controlled trial.

The purpose of this study was to document predictors of long-term retention among minority participants in the Well Elderly 2 Study, a randomized controlled trial of a lifestyle intervention for community-dwelling older adults. The primary sample included 149 African American and 92 Hispanic men and women aged 60 to 95 years, recruited at senior activity centers and senior residences. Chi-square and logistic regression procedures were undertaken to examine study-based, psychosocial and health-related predictors of retention at 18 months following study entry. For both African Americans and Hispanics, intervention adherence was the strongest predictor. Retention was also related to high active coping and average (vs. high or low) levels of activity participation among African Americans and high social network strength among Hispanics. The results suggest that improved knowledge of the predictors of retention among minority elders can spawn new retention strategies that can be applied at individual, subgroup, and sample-wide levels.

Diurnal patterns and associations among salivary cortisol, DHEA and alpha-amylase in older adults.

BACKGROUND: Cortisol and dehydroepiandrosterone (DHEA) are considered to be valuable markers of the hypothalamus-pituitary-adrenal (HPA) axis, while salivary alpha-amylase (sAA) reflects the autonomic nervous system. Past studies have found certain diurnal patterns among these biomarkers, with some studies reporting results that differ from others. Also, some past studies have found an association among these three biomarkers while other studies have not. This study investigates these patterns and associations in older adults by taking advantage of modern statistical methods for dealing with non-normality, outliers and curvature. Basic characteristics of the data are reported as well, which are relevant to understanding the nature of any patterns and associations. METHODS: Boxplots were used to check on the skewness and presence of outliers, including the impact of using simple transformations for dealing with non-normality. Diurnal patterns were investigated using recent advances aimed at comparing medians. When studying associations, the initial step was to check for curvature using a non-parametric regression estimator. Based on the resulting fit, a robust regression estimator was used that is designed to deal with skewed distributions and outliers. RESULTS: Boxplots indicated highly skewed distributions with outliers. Simple transformations (such as taking logs) did not deal with this issue in an effective manner. Consequently, diurnal patterns were investigated using medians and found to be consistent with some previous studies but not others. A positive association between awakening cortisol levels and DHEA was found when DHEA is relatively low; otherwise no association was found. The nature of the association between cortisol and DHEA was found to change during the course of the day. Upon awakening, cortisol was found to have no association with sAA when DHEA levels are relatively low, but otherwise there is a negative association. DHEA was found to have a positive association with sAA upon awakening. Shortly after awakening and for the remainder of the day, no association was found between DHEA and sAA ignoring cortisol. For DHEA and cortisol (taken as the independent variables) versus sAA (the dependent variable), again an association is found only upon awakening.

Cortisol diurnal patterns, associations with depressive symptoms, and the impact of intervention in older adults: results using modern robust methods aimed at dealing with low power due to violations of standard assumptions.

Advances in salivary bioscience enable the widespread integration of biological measures into the behavioral and social sciences. While theoretical integration has progressed, much less attention has focused on analytical strategies and tactics. The statistical literature warns that common methods for comparing groups and studying associations can have relatively poor power compared to more modern robust techniques. Here we illustrate, in secondary data analyses using the USC Well Elderly II study (n=460, age 60-95, 66% female), that modern robust methods make a substantial difference when analyzing relations between salivary analyte and behavioral data. Analyses that deal with the diurnal pattern of cortisol and the association of the cortisol awakening response with depressive symptoms and physical well-being are reported. Non-significant results become significant when using improved methods for dealing with skewed distributions and outliers. Analytical strategies and tactics that employ modern robust methods have the potential to reduce the probability of both Type I and Type II errors in studies that compare salivary analytes between groups, across time, or examine associations with salivary analyte levels.

Comparing discrete distributions when the sample space is smal / Comparando las distribuciones discretas cuando el espacio muestral es pequeño

This paper describes two new methods for comparing two independent, discrete distributions, when the sample space is small, using an extension of the Storer-Kim method for comparing independent binomials. These methods are relevant, for example, when comparing groups based on a Likert scale, which was the motivation for the paper. In essence, the goal is to test the hypothesis that the cell probabilities associated with two independent multinomial distributions are equal. Both a global test and a multiple comparison procedure are proposed. The small-sample properties of both methods are compared to four other techniques via simulations: Cliff's generalization of the Wilcoxon-Mann-Whitney test that effectively deals with heteroscedasticity and tied values, Yuen's test based on trimmed means, Welch's test and Student's t test. For the simulations, data were generated from beta-binomial distributions. Both symmetric and skewed distributions were used. The sample space consisted of the integers 0(1)4 or 0(1)10. For the global test that is proposed, when testing at the 0.05 level, simulation estimates of the actual Type I error probability ranged between 0.043 and 0.059. For the new multiple comparison procedure, the estimated family wise error rate ranged between 0.031 and 0.054 for the sample space 0(1)4. But for 0(1)10, the estimates dropped as low as 0.016 in some situations. Given the goal of comparing means, Student's t is well known to have practical problems when distributions differ. Similar problems are found here among the situations considered. No single method dominates in terms of power, as would be expected, because different methods are sensitive to different features of the distributions being compared. But in general, one of the new methods tends to have relatively good power based on both simulations and experience with data from actual studies. If, however, there is explicit interest in comparing means, rather than comparing the cell probabilities, Welch's test was found to perform well. The new methods are illustrated using data from the Well-Elderly Study where the goal is to compare groups in terms of depression and the strategies used for dealing with stress.

En este artículo se describen dos nuevos métodos para comparar dos distribuciones discretas independientes, cuando el espacio muestral es pequeño, usando una extensión del método Storer-Kim para comparar binomios independientes. Estos métodos son relevantes, por ejemplo, cuando se comparan grupos basados en una escala Likert, la cual motivó la escritura del artículo. En esencia, el objetivo es evaluar la hipótesis de que las probabilidades de células asociadas con dos distribuciones multinominales independientes son iguales. Se propone una prueba global y un procedimiento de comparación múltiple. Las propiedades de las muestras pequeñas de ambos métodos fueron comparadas con otras cuatro técnicas a través de simulaciones: generalización de Cliff de la prueba de Wilcoxon-Mann-Whitney que trata eficazmente con heteroscedasticidad y valores vinculados, la prueba de Yuen basada en medias truncadas, la prueba de Welch y la prueba t de Student. Para las simulaciones, los datos se generaron a partir de distribuciones beta-binomiales. Se utilizaron distribuciones tanto simétricas como asimétricas. El espacio muestral consistió en los enteros 0(1)4 o 0(1)10. Para la prueba global que se propone, cuando se evaluó al nivel de 0.05, la simulación estimó la probabilidad del error tipo I osciló entre 0.043 y 0.059. Para el nuevo procedimiento de comparación múltiple, la tasa de error estimada oscilaba entre 0.031 y 0.054 para el espacio de la muestra 0(1)4. Pero para 0(1)10, las estimaciones fueron tan bajas como 0.016 en algunas situaciones. Teniendo en cuenta el objetivo de la comparación de medias, la prueba t de Student es bien conocida por tener problemas prácticos cuando distribuciones difieren. Problemas similares se encuentraron entre las situaciones consideradas. No existe un único método que domina en términos de poder, como sería de esperar, debido a que los diferentes métodos son sensibles a las diferentes características de las distribuciones que son comparadas. Pero en general, uno de los nuevos métodos tiende a tener relativamente buen poder basado tanto en simulaciones y la experiencia con los datos de estudios reales. Si, sin embargo, existe un interés explícito en comparar medias, en lugar de comparar las probabilidades de celda, la prueba de Welch se encuentra que tiene un buen desempeño. Los nuevos métodos se ilustran usando datos del estudio Well-Elderly donde el objetivo es comparar los grupos en cuanto a la depresión y las estrategias utilizadas para hacer frente al estrés.