Measuring preparedness for mammography in women with intellectual disabilities: a validation study of the Mammography Preparedness Measure.

backgroundWomen with intellectual disabilities have similar breast cancer rates as the general population, but lower rates of regular mammography and higher breast cancer mortality rates. Although prior qualitative work demonstrates that women with intellectual disabilities face unique, disability-specific barriers to mammography, the present authors lack standardized, validated instruments for measuring knowledge of breast cancer screening in this population. In addition, much research related to adults with intellectual disabilities focuses on family or carer perspectives, rather than involving women with intellectual disabilities, themselves.

methodsThe present authors first pilot tested a general population instrument measuring breast cancer knowledge, and found that it did not perform adequately in women with intellectual disabilities. In response, the present authors developed the Mammography Preparedness Measure (MPM), a direct short interview tool to measure knowledge and preparedness in women with intellectual disabilities, themselves, rather than relying on caregiver or other reports, and using inclusive methodology. The present authors validated the MPM by assessing test-retest reliability.

resultsAverage test-retest per cent agreement of 84%, ranging from 74 to 91% agreement per item, with an overall kappa of 0.59.

conclusionThe MPM appears to be a valid instrument appropriate for measuring mammography preparedness in women with intellectual disabilities. The success of this innovative tool suggests that direct, rather than informant-directed tools can be developed to measure health knowledge and cancer screening readiness in adults with intellectual disabilities, an important measure in studying and reducing disparities.