Differential item functioning by language on the PROMIS® physical functioning items for children and adolescents.

PURPOSE: To assess the equivalence of self-reports of physical functioning between pediatric respondents to the English- and Spanish-language patient-reported outcomes measurement information system (PROMIS®) physical functioning item banks. METHODS: The PROMIS pediatric physical functioning item banks include 29 upper extremity items and 23 mobility items. A sample of 5091 children and adolescents (mean age = 12 years, range 8-17; 49% male) completed the English-language version of the items. A sample of 605 children and adolescents (mean age = 12 years, range 8-17; 55% male; 96% Hispanic) completed the Spanish-language version of the items. RESULTS: We found language (English versus Spanish) differential item functioning (DIF) for 4 upper extremity items and 7 mobility items. Product-moment correlations between estimated upper extremity and mobility scores using the English versus the equated Spanish item parameters for Spanish-language respondents were 0.98 and 0.99, respectively. After excluding cases with significant person misfit, we found DIF for the same 4 upper extremity items that had DIF in the full sample and for 12 mobility items (including the same 7 mobility items that had DIF in the full sample). The identification of DIF items between English- and Spanish-language respondents was affected slightly by excluding respondents displaying person misfit. CONCLUSIONS: The results of this study provide support for measurement equivalence of self-reports of physical functioning by children and adolescents who completed the English- and Spanish-language surveys. Future analyses are needed to replicate the results of this study in other samples.

Responsiveness to Change and Minimally Important Differences of the Patient-Reported Outcomes Measurement Information System Gastrointestinal Symptoms Scales.

BACKGROUND: The NIH-sponsored Patient-Reported Outcomes Measurement Information System (PROMIS) Gastrointestinal (GI) Symptoms scales were developed to assess patients' GI symptoms in clinical settings. AIMS: To assess responsiveness to change and provide minimally important difference (MID) estimates for the PROMIS GI Symptoms scales. METHODS: A sample of 256 GI outpatients self-administered the eight PROMIS GI Symptoms scales (gastroesophageal reflux, disrupted swallowing, diarrhea, bowel incontinence/soilage, nausea and vomiting, constipation, belly pain, and gas/bloating/flatulence) at two visits. Patient self-reported and physician-reported assessments of the subjects' overall GI condition were employed as change anchors. In addition, we prospectively assessed change at both visits using a GI-symptom anchor, the Gastrointestinal Symptom Rating Scale (GSRS). Responsiveness to change was assessed using F-statistics. The minimally changed group was those somewhat better or somewhat worse on the retrospective anchors and changing by one category on the modified GSRS (e.g., from slight to mild discomfort to moderate to moderately severe discomfort). RESULTS: Responsiveness to change was statistically significant for 6 of 8 PROMIS scales using the self-report GI anchor, 3 of 8 scales using the physician-reported anchor, and 5 of 5 scales using the corresponding GSRS scales as anchors. The MID estimates for scales for improvement and worsening were about 0.5-0.6 SD using the GSRS anchor and generally larger in magnitude than the change for the "about the same" group. CONCLUSIONS: The responsiveness and MID estimates provided here for the PROMIS GI Symptoms scales can aid in scale score interpretation in clinical trials and observational studies.

Differential item functioning of the patient-reported outcomes information system (PROMIS®) pain interference item bank by language (Spanish versus English).

BACKGROUND: About 70% of Latinos, 5 years old or older, in the United States speak Spanish at home. Measurement equivalence of the PROMIS® pain interference (PI) item bank by language of administration (English versus Spanish) has not been evaluated. METHODS: A sample of 527 adult Spanish-speaking Latinos completed the Spanish version of the 41-item PROMIS® pain interference item bank. We evaluate dimensionality, monotonicity and local independence of the Spanish-language items. Then we evaluate differential item functioning (DIF) using ordinal logistic regression with item response theory scores estimated from DIF-free "anchor" items. RESULTS: One of the 41 items in the Spanish version of the PROMIS® PI item bank was identified as having significant uniform DIF. CONCLUSIONS: English- and Spanish-speaking subjects with the same level of pain interference responded differently to 1 of the 41 items in the PROMIS® PI item bank. This item was not retained due to proprietary issues. The original English language item parameters can be used when estimating PROMIS® PI scores.

Development of the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) gastrointestinal symptom scales.

OBJECTIVES: The National Institutes of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS(®)) is a standardized set of patient-reported outcomes (PROs) that cover physical, mental, and social health. The aim of this study was to develop the NIH PROMIS gastrointestinal (GI) symptom measures. METHODS: We first conducted a systematic literature review to develop a broad conceptual model of GI symptoms. We complemented the review with 12 focus groups including 102 GI patients. We developed PROMIS items based on the literature and input from the focus groups followed by cognitive debriefing in 28 patients. We administered the items to diverse GI patients (irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), systemic sclerosis (SSc), and other common GI disorders) and a census-based US general population (GP) control sample. We created scales based on confirmatory factor analyses and item response theory modeling, and evaluated the scales for reliability and validity. RESULTS: A total of 102 items were developed and administered to 865 patients with GI conditions and 1,177 GP participants. Factor analyses provided support for eight scales: gastroesophageal reflux (13 items), disrupted swallowing (7 items), diarrhea (5 items), bowel incontinence/soilage (4 items), nausea and vomiting (4 items), constipation (9 items), belly pain (6 items), and gas/bloat/flatulence (12 items). The scales correlated significantly with both generic and disease-targeted legacy instruments, and demonstrate evidence of reliability. CONCLUSIONS: Using the NIH PROMIS framework, we developed eight GI symptom scales that can now be used for clinical care and research across the full range of GI disorders.

Evaluation of the Patient-Reported Outcomes Information System (PROMIS(®)) Spanish-language physical functioning items.

PURPOSE: To evaluate the equivalence of the PROMIS(®) physical functioning item bank by language of administration (English versus Spanish). METHODS: The PROMIS(®) wave 1 English-language physical functioning bank consists of 124 items, and 114 of these were translated into Spanish. ANALYSIS: Item frequencies, means and standard deviations, item-scale correlations, and internal consistency reliability were calculated. The IRT assumption of unidimensionality was evaluated by fitting a single-factor confirmatory factor analytic model. IRT threshold and discrimination parameters were estimated using Samejima's Graded Response Model. DIF by language of administration was evaluated. RESULTS: Item means ranged from 2.53 (SD = 1.36) to 4.62 (SD = 0.82). Coefficient alpha was 0.99, and item-rest correlations ranged from 0.41 to 0.89. A one-factor model fits the data well (CFI = 0.971, TLI = 0.970, and RMSEA = 0.052). The slope parameters ranged from 0.45 ("Are you able to run 10 miles?") to 4.50 ("Are you able to put on a shirt or blouse?"). The threshold parameters ranged from -1.92 ("How much do physical health problems now limit your usual physical activities (such as walking or climbing stairs)?") to 6.06 ("Are you able to run 10 miles?"). Fifty of the 114 items were flagged for DIF based on an R(2) of 0.02 or above criterion. The expected total score was higher for Spanish- than English-language respondents. CONCLUSIONS: English- and Spanish-speaking subjects with the same level of underlying physical function responded differently to 50 of 114 items. This study has important implications in the study of physical functioning among diverse populations.

Development of a vision-targeted health-related quality of life item measure.

PURPOSE: To develop a vision-targeted health-related quality of life (HRQOL) measure for the NIH Toolbox for the Assessment of Neurological and Behavioral Function. METHODS: We conducted a review of existing vision-targeted HRQOL surveys and identified color vision, low luminance vision, distance vision, general vision, near vision, ocular symptoms, psychosocial well-being, and role performance domains. Items in existing survey instruments were sorted into these domains. We selected non-redundant items and revised them to improve clarity and to limit the number of different response options. We conducted 10 cognitive interviews to evaluate the items. Finally, we revised the items and administered them to 819 individuals to calibrate the items and estimate the measure's reliability and validity. RESULTS: The field test provided support for the 53-item vision-targeted HRQOL measure encompassing 6 domains: color vision, distance vision, near vision, ocular symptoms, psychosocial well-being, and role performance. The domain scores had high levels of reliability (coefficient alphas ranged from 0.848 to 0.940). Validity was supported by high correlations between National Eye Institute Visual Function Questionnaire scales and the new-vision-targeted scales (highest values were 0.771 between psychosocial well-being and mental health, and 0.729 between role performance and role difficulties), and by lower mean scores in those groups self-reporting eye disease (F statistic with p < 0.01 for all comparisons except cataract with ocular symptoms, psychosocial well-being, and role performance scales). CONCLUSIONS: This vision-targeted HRQOL measure provides a basis for comprehensive assessment of the impact of eye diseases and treatments on daily functioning and well-being in adults.

Vision-Targeted Health-Related Quality-of-Life Survey for Evaluating Minimally Invasive Glaucoma Surgery.

PURPOSE: To develop a vision-targeted health-related quality-of-life instrument for patients with glaucoma who are candidates for minimally invasive glaucoma surgery (MIGS). DESIGN: Development of a health-related quality-of-life instrument. PARTICIPANTS: Twelve practicing ophthalmologists and 41 glaucoma patients. METHODS: A questionnaire was constructed to assess functional limitations, vision-related symptoms, aesthetics, psychosocial issues, and surgical satisfaction for MIGS candidates. Questions were drafted after a review of the literature and subsequently refined based upon input from 1 physician and 4 patient focus groups. Nineteen cognitive interviews were used to ensure that questions were understandable to respondents. RESULTS: The focus group identified the following key issues and concerns as being important to glaucoma patients: functional limitations (eg, driving), bodily discomfort (eg, stinging from drops), changes in appearance (eg, drooping eyelid), and psychosocial concerns (eg, mental burden associated with a diagnosis of glaucoma, financial burden of treatment). Cognitive interviews resulted in the following improvements to the questionnaire: changes in wording to clarify lighting conditions, and additional questions addressing psychosocial issues, such as job loss, severity of disease, and perception of MIGS. CONCLUSIONS: A patient-reported outcomes instrument, the Glaucoma Outcomes Survey, was developed to evaluate MIGS for patients with mild to moderate glaucoma. Next steps include electronic administration to patients selected from the American Academy of Ophthalmology Intelligent Research in Sight (IRIS) registry. An electronic patient-reported outcomes platform will be used to administer the questionnaire before and after MIGS. The questionnaire will improve understanding of how surgical interventions such as MIGS impact vision-targeted health-related quality-of-life in glaucoma patients.

Self-reported use of eye care among Latinos: the Los Angeles Latino Eye Study.

PURPOSE: To identify the prevalence and determinants of self-reported eye care use in Latinos. DESIGN: Population-based ocular epidemiologic study in Latinos aged 40+ years living in La Puente, California. PARTICIPANTS: A total of 5455 participants. METHODS: Univariate, multivariable, and stepwise logistic regression analyses were conducted to identify predisposing, enabling, and need variables associated with self-reported eye care use. MAIN OUTCOME MEASURES: Prevalence of self-reported use: eye care visit, having had a dilated examination in the past 12 months, ever having had a dilated examination, and odds ratios for factors associated with self-reported use. RESULTS: Overall, 36% of participants reported an eye care visit and 19% reported having a dilated examination in the past year. Fifty-seven percent reported ever having had a dilated eye examination. Greater eye care use was associated with older age, female gender, bilingual language proficiency (English and Spanish), more education, having health insurance, having a usual place for care, having a regular provider of care, a greater number of comorbidities, visual impairment, and lower vision-specific quality of life scores. CONCLUSIONS: Multiple modifiable factors are associated with greater use and access to eye care for Latinos. Modification of these factors should be a priority because visual impairment has significant impacts on well-being and mortality.

Readability estimates for commonly used health-related quality of life surveys.

PURPOSE: To estimate readability of seven commonly used health-related quality of life instruments: SF-36, HUI, EQ-5D, QWB-SA, HALex, Minnesota Living with Heart Failure Questionnaire (MLHFQ), and the NEI-VFQ-25. METHODS: The Flesch-Kincaid (F-K) and Flesch Reading Ease (FRE) formulae were used to estimate readability for every item in each measure. RESULTS: The percentage of items that require more than 5 years of formal schooling according to F-K was 50 for the EQ-5D, 53 for the SF-36, 80 for the VFQ-25, 85 for the QWB-SA, 100 for the HUI, HALex, and the MLHFQ. The percentage of items deemed harder than "easy" according to FRE was 50 for the SF-36, 67 for the EQ-5D, 79 for the QWB-SA, 80 for the VFQ-25, 100 for the HUI, HALex, and the MLHFQ. CONCLUSIONS: All seven surveys have a substantial number of items with high readability levels that may not be appropriate for the general population.

Readability and Comprehension of the Geriatric Depression Scale and PROMIS® Physical Function Items in Older African Americans and Latinos.

BACKGROUND: Depression and physical function are particularly important health domains for the elderly. The Geriatric Depression Scale (GDS) and the Patient-Reported Outcomes Measurement Information System (PROMIS®) physical function item bank are two surveys commonly used to measure these domains. It is unclear if these two instruments adequately measure these aspects of health in minority elderly. OBJECTIVE: The aim of this study was to estimate the readability of the GDS and PROMIS® physical function items and to assess their comprehensibility using a sample of African American and Latino elderly. METHODS: Readability was estimated using the Flesch-Kincaid and Flesch Reading Ease (FRE) formulae for English versions, and a Spanish adaptation of the FRE formula for the Spanish versions. Comprehension of the GDS and PROMIS® items by minority elderly was evaluated with 30 cognitive interviews. RESULTS: Readability estimates of a number of items in English and Spanish of the GDS and PROMIS® physical functioning items exceed the U.S. recommended 5th-grade threshold for vulnerable populations, or were rated as 'fairly difficult', 'difficult', or 'very difficult' to read. Cognitive interviews revealed that many participants felt that more than the two (yes/no) GDS response options were needed to answer the questions. Wording of several PROMIS® items was considered confusing, and interpreting responses was problematic because they were based on using physical aids. CONCLUSIONS: Problems with item wording and response options of the GDS and PROMIS® physical function items may reduce reliability and validity of measurement when used with minority elderly.

Noncompliance with vision care guidelines in Latinos with type 2 diabetes mellitus: the Los Angeles Latino Eye Study.

OBJECTIVE: To determine the prevalence of and personal factors associated with noncompliance with American Diabetes Association (ADA) guidelines for vision care in a population-based sample of adult Latinos with type 2 diabetes mellitus (T2DM). DESIGN: Population-based cross-sectional study. PARTICIPANTS: Eight hundred twenty-one Los Angeles Latino Eye Study (LALES) participants with a history of T2DM and a history of treatment for T2DM. METHODS: Detailed interviews, physical examinations, and dilated eye examinations were performed on all participants. Interviews assessed sociodemographic factors, history of diabetes and eye disease, and utilization of health and eye care services. All participants with a self-reported history and treatment of diabetes were asked about health and vision care utilization and diabetes self-care. MAIN OUTCOME MEASURE: Compliance with ADA guidelines for vision care. Noncompliance was defined as having had no dilated eye examination in the previous 12 months. Logistic regression analyses were used to identify personal factors associated with noncompliance. RESULTS: Of 821 individuals who self-reported having T2DM and being on treatment for T2DM, 535 (65%) had not complied with ADA vision guidelines for persons with T2DM. When compared with those with T2DM who complied with ADA guidelines, noncompliers were more likely to be less educated (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1-2.2), to lack health insurance (OR, 2.5; 95% CI, 1.7-3.7), to have had no routine physical examination in the 12 months before the LALES examination (OR, 1.8; 95% CI, 1.3-2.5), and to have a glycosylated hemoglobin level > or = 9.0% (OR, 1.7; 95% CI, 1.1-2.6). CONCLUSIONS: Because timely and appropriate vision care can delay the onset of ocular morbidity, visual impairment, and blindness associated with diabetic retinopathy, our data suggest the need to evaluate intervention programs aimed at a targeted group of Latinos with T2DM--those who have less than a high school education, lack health insurance, have had no routine physical examination in the previous year, and have poorly controlled T2DM.

The multi-ethnic pediatric eye disease study: design and methods.

PURPOSE: To summarize the study design of the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS). METHODS: The objectives of the MEPEDS are to: (1) estimate age- and ethnicity-specific prevalence of strabismus, amblyopia, and refractive error; (2) evaluate the association of selected risk factors with these ocular disorders; and (3) evaluate the association of ocular conditions on limitations in health-related functional status in a population-based sample of 12,000 children aged 6-72 months from four ethnic groups--African-American, Asian-American, Hispanics/Latinos and non-Hispanic White. Each eligible child undergoes an eye examination, which includes an interview with his/her parent. The interview includes an assessment of demographic, behavioral, biological, and ocular risk factors and health-related functional status. The examination includes fixation preference testing, visual acuity, stereoacuity, axial length measurement, cycloplegic refraction, keratometry, eye alignment, and anterior and posterior segment examination.

Relationship between self-reported depression and self-reported visual function in Latinos.

OBJECTIVE: To validate and assess the relationship between self-reported depression as measured by a single item on the Medical Outcomes Study Short-Form 12 (SF-12) and self-reported visual function. METHODS: The Los Angeles Latino Eye Study is population-based and designed to assess the prevalence of visual impairment, ocular disease, and visual functioning in Latinos. Both the 25-item National Eye Institute-Visual Function Questionnaire (NEI VFQ-25) (self-reported visual function) and the SF-12 (health-related quality of life) were administered. A single item from the SF-12 was used to measure self-reported depression and validated against the Center for Epidemiologic Studies-Depression measure of depression. Covariate-adjusted NEI VFQ-25 subscale scores were contrasted across the 6 response choices of the SF-12, as well as across 3 combined response categories of the SF-12 using analysis of covariance. Covariate-adjusted regression analyses assessed the contribution of self-reported depression in explaining self-reported visual function. RESULTS: The sensitivity and specificity of the SF-12 single item with the Center for Epidemiologic Studies-Depression measure was 0.96 and 0.50, respectively. Using the 3 combined response categories of the SF-12 single item, it was found that (1) all covariate-adjusted subscales of the NEI VFQ-25 were statistically significantly different across the self-reported depression categories (P<.001) and (2) covariate-adjusted self-reported depression was a significant predictor of self-reported visual function (P<.001). CONCLUSIONS: A single SF-12 item may be used as a measure of self-reported depression. In addition, self-reported depression is an important covariate to consider when assessing self-reported visual function in Latinos.

Age-related Differential Item Functioning for the Patient-Reported Outcomes Information System (PROMIS®) Physical Functioning Items.

PURPOSE: To evaluate the equivalence of the PROMIS® wave 1 physical functioning item bank, by age (50 years or older versus 18-49). MATERIALS AND METHODS: A total of 114 physical functioning items with 5 response choices were administered to English- (n=1504) and Spanish-language (n=640) adults. Item frequencies, means and standard deviations, item-scale correlations, and internal consistency reliability were estimated. Differential Item Functioning (DIF) by age was evaluated. RESULTS: Thirty of the 114 items were fagged for DIF based on an R-squared of 0.02 or above criterion. The expected total score was higher for those respondents who were 18-49 than those who were 50 or older. CONCLUSIONS: Those who were 50 years or older versus 18-49 years old with the same level of physical functioning responded differently to 30 of the 114 items in the PROMIS® physical functioning item bank. This study yields essential information about the equivalence of the physical functioning items in older versus younger individuals.

The Los Angeles Latino Eye Study: design, methods, and baseline data.

OBJECTIVE: To describe the study design, operational strategies, procedures, and baseline characteristics of the Los Angeles Latino Eye Study (LALES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Latinos. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California. METHODS: A detailed interview and eye examination were performed on each eligible participant. The interview included an assessment of demographic, behavioral, and ocular risk factors and health-related and vision-related quality of life. The eye examination included a measurement of visual acuity, intraocular pressure, and visual fields; fundus and optic disc photography; a detailed anterior and posterior segment examination; and measurement of blood pressure, glycosylated hemoglobin levels, and blood glucose levels. MAIN OUTCOME MEASURES: Prevalence of visual impairment, blindness, cataract, glaucoma, diabetic retinopathy, and age-related macular degeneration constitute the study's primary outcome variables. Secondary outcomes include odds ratios for risk factors associated with eye disease, health-related quality of life, and vision-related quality of life. Response rates and baseline characteristics are presented. RESULTS: Of the 7789 individuals eligible for LALES, 6357 (82%) had a clinical examination; an additional 524 completed only an in-home interview. The majority of participants were female (58%), the average (+/- standard deviation) age was 54.9 (+/-10.8) years, and 80.0% were of Mexican origin and 0.4% self-identified as American Indian or Alaskan Native. The age distribution of LALES participants was similar to that of Latinos of Mexican origin in the rest of the United States. CONCLUSION: The LALES has recruited Latinos 40 and older for an ophthalmic epidemiologic study. The LALES cohort will provide information about the prevalence and risk factors of ocular disease in the largest and fastest growing minority in the United States.