Robert F. Devellis

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The development of the Multidimensional Health Locus of Control scales is described. Scales have been developed to tap beliefs that the source of reinforcements for health-related behaviors is primarily internal, a matter of chance, or under the control of powerful others. These scales are based on earlier work with a general Health Locus of Control Scale,(More)
OBJECTIVES Patient-reported outcomes (PROs) are essential when evaluating many new treatments in health care; yet, current measures have been limited by a lack of precision, standardization, and comparability of scores across studies and diseases. The Patient-Reported Outcomes Measurement Information System (PROMIS) provides item banks that offer the(More)
Measuring only the physical markers of violence (e.g., slapping, beating) fails to capture the chronic vulnerability and gendered nature of battered women's experiences. Instruments that measure only observable discrete events may mask the continuous nature of battering and the relation between events and experience. Our approach to measuring battering(More)
OBJECTIVES To achieve the Healthy People 2000 objectives, public health professionals must develop effective dietary interventions that address psychosocial and behavioral components of change. This study tested the effect of individually computer-tailored messages designed to decrease fat intake and increase fruit and vegetable intake. METHODS Adult(More)
STUDY DESIGN A systematic review was conducted. OBJECTIVE To identify, evaluate, and compare standard scales for assessing neck pain or dysfunction. SUMMARY OF BACKGROUND DATA The degree of a patient's neck pain or dysfunction can be evaluated using standardized scales at the time of a clinical encounter or during the performance of clinical research(More)
BACKGROUND Online social networks, such as Facebook™, have extensive reach, and they use technology that could enhance social support, an established determinant of physical activity. This combination of reach and functionality makes online social networks a promising intervention platform for increasing physical activity. PURPOSE To test the efficacy of(More)
Classical test theory (CTT) comprises a set of concepts and methods that provide a basis for many of the measurement tools currently used in health research. The assumptions and concepts underlying CTT are discussed. These include item and scale characteristics that derive from CTT as well as types of reliability and validity. Procedures commonly used in(More)
Using data from 3 studies of patients with rheumatoid arthritis, we examined the extent to which responses to items in the Center for Epidemiological Studies Depression Scale (CES-D) are influenced by aspects of the disease process other than depression. Our findings suggested that 4 CES-D items (i.e., "I felt that everything I did was an effort," "I felt(More)
BACKGROUND Although African Americans are disproportionately affected by the AIDS epidemic, they are underrepresented in AIDS research, particularly in AIDS clinical trials. This study examines a multidimensional construct of distrust and other factors that may affect willingness to participate in AIDS research. METHODS A total of 301 African Americans(More)