Patients and Medical Statistics

Interest, Confidence, and Ability

Authors

  • Steven Woloshin MD, MS,

    1. The VA Outcomes Group (111B), Department of Veterans Affairs Medical Center, White River Junction, Vt, USA
    2. The Center for the Evaluative Clinical Sciences, Dartmouth Medical School, Hanover, NH, USA.
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  • Lisa M. Schwartz MD, MS,

    1. The VA Outcomes Group (111B), Department of Veterans Affairs Medical Center, White River Junction, Vt, USA
    2. The Center for the Evaluative Clinical Sciences, Dartmouth Medical School, Hanover, NH, USA.
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  • H. Gilbert Welch MD, MPH

    1. The VA Outcomes Group (111B), Department of Veterans Affairs Medical Center, White River Junction, Vt, USA
    2. The Center for the Evaluative Clinical Sciences, Dartmouth Medical School, Hanover, NH, USA.
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  • The authors have no conflicts of interest to declare for this article or this research.

  • Dr. Schwartz is supported by Veterans Affairs Career Development Awards in Health Services Research and Development. Drs. Schwartz and Woloshin are supported by Robert Wood Johnson Generalist Faculty Scholar Awards and National Cancer Institute grants #CA91052-01 and CA104721. All the authors are supported by a Research Enhancement Award from the Department of Veterans Affairs. The views expressed herein do not necessarily represent the views of the Department of Veterans Affairs or the United States Government.

Address correspondence and requests for reprints to Dr. Woloshin: VA Outcomes Group (111B), Department of Veterans Affairs Medical Center, White River Junction, VT 05009 (e-mail: steven.woloshin@dartmouth.edu).

Abstract

Background: People are increasingly presented with medical statistics. There are no existing measures to assess their level of interest or confidence in using medical statistics.

Objective: To develop 2 new measures, the STAT-interest and STAT-confidence scales, and assess their reliability and validity.

Design: Survey with retest after approximately 2 weeks.

Subjects: Two hundred and twenty-four people were recruited from advertisements in local newspapers, an outpatient clinic waiting area, and a hospital open house.

Measures: We developed and revised 5 items on interest in medical statistics and 3 on confidence understanding statistics.

Results: Study participants were mostly college graduates (52%); 25% had a high school education or less. The mean age was 53 (range 20 to 84) years. Most paid attention to medical statistics (6% paid no attention). The mean (SD) STAT-interest score was 68 (17) and ranged from 15 to 100. Confidence in using statistics was also high: the mean (SD) STAT-confidence score was 65 (19) and ranged from 11 to 100. STAT-interest and STAT-confidence scores were moderately correlated (r=.36, P<.001). Both scales demonstrated good test–retest repeatability (r=.60, .62, respectively), internal consistency reliability (Cronbach's α=0.70 and 0.78), and usability (individual item nonresponse ranged from 0% to 1.3%). Scale scores correlated only weakly with scores on a medical data interpretation test (r=.15 and .26, respectively).

Conclusion: The STAT-interest and STAT-confidence scales are usable and reliable. Interest and confidence were only weakly related to the ability to actually use data.

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