+Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life
<p>Abstract</p> <p>Background</p> <p>The MacDQoL is an individualised measure of the impact of macular degeneration (MD) on quality of life (QoL). There is preliminary evidence of its psychometric properties and sensitivity to severity of MD. The aim of this study was t...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2005-04-01
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| Series: | Health and Quality of Life Outcomes |
| Online Access: | http://www.hqlo.com/content/3/1/25 |
| _version_ | 1811315076565565440 |
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| author | ffytche Timothy McMillan Carolyn V Anderson Stephen J Woodcock Alison Wolffsohn James S Mitchell Jan Rubinstein Martin Amoaku Winfried Bradley Clare |
| author_facet | ffytche Timothy McMillan Carolyn V Anderson Stephen J Woodcock Alison Wolffsohn James S Mitchell Jan Rubinstein Martin Amoaku Winfried Bradley Clare |
| author_sort | ffytche Timothy |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>The MacDQoL is an individualised measure of the impact of macular degeneration (MD) on quality of life (QoL). There is preliminary evidence of its psychometric properties and sensitivity to severity of MD. The aim of this study was to carry out further psychometric evaluation with a larger sample and investigate the measure's sensitivity to MD severity.</p> <p>Methods</p> <p>Patients with MD (n = 156: 99 women, 57 men, mean age 79 ± 13 years), recruited from eye clinics (one NHS, one private) completed the MacDQoL by telephone interview and later underwent a clinic vision assessment including near and distance visual acuity (VA), comfortable near VA, contrast sensitivity, colour recognition, recovery from glare and presence or absence of distortion or scotoma in the central 10° of the visual field.</p> <p>Results</p> <p>The completion rate for the MacDQoL items was 99.8%. Of the 26 items, three were dropped from the measure due to redundancy. A fourth was retained in the questionnaire but excluded when computing the scale score. Principal components analysis and Cronbach's alpha (0.944) supported combining the remaining 22 items in a single scale. Lower MacDQoL scores, indicating more negative impact of MD on QoL, were associated with poorer distance VA (better eye r = -0.431 p < 0.001; worse eye r = -0.350 p < 0.001; binocular vision r = -0.419 p < 0.001) and near VA (better eye r = -0.326 p < 0.001; worse eye r = -0.226 p < 0.001; binocular vision r = -0.326 p < 0.001). Poorer MacDQoL scores were associated with poorer contrast sensitivity (better eye r = 0.392 p < 0.001; binocular vision r = 0.423 p < 0.001), poorer colour recognition (r = 0.417 p < 0.001) and poorer comfortable near VA (r = -0.283, p < 0.001). The MacDQoL differentiated between those with and without binocular scotoma (U = 1244 p < 0.001).</p> <p>Conclusion</p> <p>The MacDQoL 22-item scale has excellent internal consistency reliability and a single-factor structure. The measure is acceptable to respondents and the generic QoL item, MD-specific QoL item and average weighted impact score are related to several measures of vision. The MacDQoL demonstrates that MD has considerable negative impact on many aspects of QoL, particularly independence, leisure activities, dealing with personal affairs and mobility. The measure may be valuable for use in clinical trials and routine clinical care.</p> |
| first_indexed | 2024-04-13T11:23:49Z |
| format | Article |
| id | doaj.art-0369ea6a6317472c8d0b18dfe4ebe364 |
| institution | Directory Open Access Journal |
| issn | 1477-7525 |
| language | English |
| last_indexed | 2024-04-13T11:23:49Z |
| publishDate | 2005-04-01 |
| publisher | BMC |
| record_format | Article |
| series | Health and Quality of Life Outcomes |
| spelling | doaj.art-0369ea6a6317472c8d0b18dfe4ebe3642022-12-22T02:48:44ZengBMCHealth and Quality of Life Outcomes1477-75252005-04-01312510.1186/1477-7525-3-25+Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of lifeffytche TimothyMcMillan Carolyn VAnderson Stephen JWoodcock AlisonWolffsohn James SMitchell JanRubinstein MartinAmoaku WinfriedBradley Clare<p>Abstract</p> <p>Background</p> <p>The MacDQoL is an individualised measure of the impact of macular degeneration (MD) on quality of life (QoL). There is preliminary evidence of its psychometric properties and sensitivity to severity of MD. The aim of this study was to carry out further psychometric evaluation with a larger sample and investigate the measure's sensitivity to MD severity.</p> <p>Methods</p> <p>Patients with MD (n = 156: 99 women, 57 men, mean age 79 ± 13 years), recruited from eye clinics (one NHS, one private) completed the MacDQoL by telephone interview and later underwent a clinic vision assessment including near and distance visual acuity (VA), comfortable near VA, contrast sensitivity, colour recognition, recovery from glare and presence or absence of distortion or scotoma in the central 10° of the visual field.</p> <p>Results</p> <p>The completion rate for the MacDQoL items was 99.8%. Of the 26 items, three were dropped from the measure due to redundancy. A fourth was retained in the questionnaire but excluded when computing the scale score. Principal components analysis and Cronbach's alpha (0.944) supported combining the remaining 22 items in a single scale. Lower MacDQoL scores, indicating more negative impact of MD on QoL, were associated with poorer distance VA (better eye r = -0.431 p < 0.001; worse eye r = -0.350 p < 0.001; binocular vision r = -0.419 p < 0.001) and near VA (better eye r = -0.326 p < 0.001; worse eye r = -0.226 p < 0.001; binocular vision r = -0.326 p < 0.001). Poorer MacDQoL scores were associated with poorer contrast sensitivity (better eye r = 0.392 p < 0.001; binocular vision r = 0.423 p < 0.001), poorer colour recognition (r = 0.417 p < 0.001) and poorer comfortable near VA (r = -0.283, p < 0.001). The MacDQoL differentiated between those with and without binocular scotoma (U = 1244 p < 0.001).</p> <p>Conclusion</p> <p>The MacDQoL 22-item scale has excellent internal consistency reliability and a single-factor structure. The measure is acceptable to respondents and the generic QoL item, MD-specific QoL item and average weighted impact score are related to several measures of vision. The MacDQoL demonstrates that MD has considerable negative impact on many aspects of QoL, particularly independence, leisure activities, dealing with personal affairs and mobility. The measure may be valuable for use in clinical trials and routine clinical care.</p>http://www.hqlo.com/content/3/1/25 |
| spellingShingle | ffytche Timothy McMillan Carolyn V Anderson Stephen J Woodcock Alison Wolffsohn James S Mitchell Jan Rubinstein Martin Amoaku Winfried Bradley Clare +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life Health and Quality of Life Outcomes |
| title | +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life |
| title_full | +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life |
| title_fullStr | +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life |
| title_full_unstemmed | +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life |
| title_short | +Psychometric evaluation of the MacDQoL individualised measure of the impact of macular degeneration on quality of life |
| title_sort | psychometric evaluation of the macdqol individualised measure of the impact of macular degeneration on quality of life |
| url | http://www.hqlo.com/content/3/1/25 |
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