動画で説明:https://youtu.be/rTIPekfKyV4
MID:Minimally Important Difference
MCID:Minimum Clinically Important Difference
についての説明
追加:
文献4の中等度・著明改善の群分けは、以下にありました。また、1-7段階でなく、-7~7
という変ったGRCS ですね。
2.5. Data processing and statistical analysis
Subjects were classified as having no improvement when their responses to the GRCS were between -7 and 0, moderate improvement between 1 and 3 and large improvement between 4 and 7 after the treatment. Thus, the anchor-method approach was used to estimate the MCID of each of the outcome variables of interest (e.g. VAS, PPTs, HIT-6, CCFT) using the GRCS as the anchor.
動画で説明:https://youtu.be/rTIPekfKyV4
MID:Minimally Important Difference
MCID:Minimum Clinically Important Difference
についての説明
追加:
文献4の中等度・著明改善の群分けは、以下にありました。また、1-7段階でなく、-7~7
という変ったGRCS ですね。
2.5. Data processing and statistical analysis
Subjects were classified as having no improvement when their responses to the GRCS were between -7 and 0, moderate improvement between 1 and 3 and large improvement between 4 and 7 after the treatment. Thus, the anchor-method approach was used to estimate the MCID of each of the outcome variables of interest (e.g. VAS, PPTs, HIT-6, CCFT) using the GRCS as the anchor.
12. 記載例:手首の問題の症状重症度尺度に関する反
応性の検討(Spies-Dorgelo et al. ,2006, Health and quality of life
outcomes)
12
<Methods>
対象者は手や手首に問題を抱えた84名(→良いサンプルサイズ)“The
baseline and 3-month follow-up data were used to assess
responsiveness”(→3ヶ月の縦断的デザインの使用)
<Results>
“Very few patients reported a deterioration in daily functioning, and we
therefor clustered the scores of patients reporting little, much or very
much deterioration. ”(→患者変化あり,関連するイベントは記載なし)
18. 事前に反応性のレベルを設定する
• 尺度の変化がゴールドスタンダードの変化とどのく
らい一致すれば反応性ありとするか事前に設定
※一致は高いことが望ましいが,測定誤差により,相関が低く
なることも考慮しておく。
18
Tamber et al. (2009) , Health and quality of life outcomes
めまいハンディキャップ尺度(DHI-N)の反応性
ゴールドスタンダード:障害度尺度(めまいに関連した障害度のGRS)
<method>
The Disability Scale seemed appropriate to use as an external anchor to examine
discriminate ability and responsiveness to important change of DHI-N <中略>
Responsiveness of the DHI-N was also examined by using an anchor-based method.
Scores on the Disability Scale were used as an external criterion for important
change in the construct being measured, and its applicability was considered
adequate, if changes in scores in the DHI-N and the Disability Scale correlated with r
≧0.50.
20. 記載例:めまいハンディキャップ尺度(DHI-N)の反応性
(Tamber et al., 2009 , Health and quality of life outcomes)
20
検討する尺度:めまいハンディキャップ尺度(DHI-N)
ゴールドスタンダード:障害度尺度(めまいに関連した障害度のGRS)
事前に設定した相関の強さは前述の通り。ROCは以下に記載。
<Methods>
Change scores of the DHI-N were explored in ROC curve analyses using this
dichotomized scale of ‘improved’ and ‘unchanged’ participants as dependent
variable. The AUC was used as measure of responsiveness, and AUC > 0.70 is
considered adequate.
<Results>
The Disability scale was found suitable as an external criterion of change in
construct being measured, r being 0.51. The Scale demonstrated excellent ability to
discriminate between ‘improved’ and ‘unchanged’ participants according to the
area under the ROC curve: AUC being 0.83 (95% CI: 0.71-0.94).
25. 記載例:視覚関連QOL尺度(VCM1)の反応性の
検討(De Boer et al. (2006). Quality of life research)
<Hypothesis>
We used to assess responsiveness was
to postulate specific hypotheses about
the relations we expected between the
VCM1 and other measures and to test
these. The hypotheses (Table2) will be
discussed in more detail below.
<Results>
Table2 gives the results of the
evaluation of hypotheses we
postulated to test the responsiveness.
<中略>The percentage of correlations
that were refuted were 50%
(moderate) for VMC1.
25
VMC1の得点変化に関する仮説 相関係数 確
認
①白内障用視覚機能尺度の変
化得点との相関は,②視覚に関
する知覚された変化得点間の相
関よりも0.1高い
①0.39
②0.19
Yes
・
・
・
①遠見視力(5m以上の距離測
定)の変化得点との相関は,②
Euroqol (健康関連QOL尺度)の変
化得点との相関より0.1高い
①-0.02
②0.26
No
棄却された仮説のパーセント 3/6 = 50%
対象:視覚に障害のある老人329名
測定:ベースラインと5ヶ月後にデータ取得
27. 記載例:視覚関連QOL尺度(VCM1)の反応性の
検討(De Boer et al. (2006). Quality of life research)
仮説検定に用いた比較尺度の記載例
The Euroqol.
It is an extensively validated generic HRQOL questionnaire that was
developed in the Netherlands and several other European countries at the
same time[17]. It consists of the respondent’s classification of health state on
five broad dimensions and a rating of his/her health by means of a
thermometer. Construct validity and reproducibility appeared to be
good[17,18]. In our sample, the ICCagreement for the thermometer was 0.75
(N=164), the kappa’s for the five health state dimentions ranged from 0.47 to
0.69 (N=150-152)(0.63 for mobility).
27
38. 記載例:首の痛み障害尺度のラッシュ分析(Van
der Velde et al., 2009, Arthritis and rheumatism)
38
尺度:首の痛み障害尺度(Neck Disability Index)
対象者:首の痛みをもった患者512名
<Results>
The targeting of the NDI-8 item thresholds for subjects in our sample is shown
in Figure 2. There is good coverage of thresholds over the breadth of neck
pain-related disability.・・・our sample is centered over the lower end of the
neck pain disability scale・・・
この辺の項目はこ
のサンプルでは意
味を持たない。
全体的に低い特性
値に分布している。
しかし,低特性値
には項目が少ない。
40. 記載例:(Spies-Dorgelo et al., 2006, Health and quality of
life outcomes)
40
対象:プライマリケアで手と手首に問題のある患者におけ
る症状重症度尺度と身体機能尺度(AIMS2の手指の機能)
<Method>We assessed the presence of floor and ceiling effects, by
examining the frequency of the highest and lowest possible scores at
baseline. Floor effects were considered to be present if more than 15%
of the patients had a minimal score at baseline・・・(天井効果も同様)
<Results>We found a floor effect for the Dutch-AIMS2-HF; 30% of
the patients had a minimum score of 0 at baseline.
44. 変化得点の解釈
①最小限の重要な変化(Minimal important change:
MIC)※de Vet et al(2011)はこちらを推奨
→患者や臨床家が重要と感じるような最小限の変化
→重要な変化の外的基準(アンカー)に基づくアプロー
チ
②検出可能な最小限の変化(Minimal Detectable
Change: MDC)
→測定誤差を超えるような最小限の変化
→尺度の変化得点の分布に基づくアプローチ
44Crosby et al., 2003, J. Clin Epidemiol
49. 最小限の重要な変化
Visual anchor-based MIC distribution
①アンカーに基づいて対象者を分割
→重要な変化をした患者群,重要な変化をし
てない患者群,重要な悪化を示した患者群
②変化得点の分布をプロットする
→重要な変化のあった群の分布を左,変化の
群の分布を右にプロット
*群のサンプルサイズの違いが影響しないよ
うに,絶対頻度でなく比率度数を使う
③カットオフポイントを決定する
ROC分析:感度と特異度を最大にする
カットオフポイントを決定=MIC
95%上限:重要な改善なし群の95%上
限(変化得点平均+1.645*SD)=MIC
49
De Vet et al., Quality of Life Res, 2007
アンカー
重要な改善 重要な改善
なし
重要な悪化
重要な改
善の分布
重要な悪
化の分布
←95%上限
←ROC
←95%下限
←ROC
50. 最小限の重要な変化
Visual anchor-based MIC distribution
• Visual anchor-based MIC
distributionでは分布を確
認することが大切。
• 左図も右図もMICは一緒だ
が,分布はかなり異なる。
• 場合によっては,変化して
ないとう偽陰性を問題にす
る時もある(例えば,変化
が認められない時は侵襲
的治療を行う場合),その
時は,重み付けもできる。 50
De Vet et al., J Clinical Epidemiology, 2010
51. 記載例:緊張性尿失禁の女性患者における
PRAFAB質問票の最小限の重要な変化
(Hendriks et al., 2008, Neurourology and Urodynamics)
51
対象患者:緊張性尿失禁をもつ女性患者279名
PRAFAB質問票:失禁対策・量・頻度・活動支障度・自己イメージの5
項目4件法,高いほど重症,ベースラインと12週後に測定
アンカー:12週後にベースラインからの全体的な変化を問うGRS
<Method>
・MIC distribution法の記載例
To estimate the MIC we used the ROC method and the 95% limit cut-off point,
visualized by the ‘anchor based MIC distribution’ as described by De Vet et al. To
analyze the results, we produced separate graphs for the total and stratified
analysis to show the distribution (expressed in percentage) of patients who were
‘importantly improved’ and those who were ’not importantly improved’.
・GRSで ’moderately better’・’much better’・’very much better’は,’importantly
improved’とする。’slightly better’・’about the same’・’slightly worse’
は, ’unchaged’とする。
52. 記載例:緊張性尿失禁の女性患者における
PRAFAB質問票の最小限の重要な変化
(Hendriks et al., 2008, Neurourology and Urodynamics)
52
<Results>
The MIC defined by the ROC method and
95% limit cut-off point corresponds to a
change score of 2.5 points and 3.2 points,
respectively.
<重症度による層別解析>
MICはベースラインの高さによって変化す
るので,ベースラインの重症度で2群に
わけてMICを算出。(重症度群MICROC=4.0,
軽症群MICROC=2.0)
57. 参考・引用文献
• De Vet, Terwee, Mokkink, & Knol
(2011) “Measurment in Medicine”,
Cambridge University Press.
• COSMIN Checklist
• 尺度特性を検討した研究は探すの
が難しい。サーチフィルターによって
記載例を探す。
Terwee et al. (2009).Development of a
methodological PubMed search filter
for finding studies on measurement
properties of measurement
instruments. Quality of life research,
18(8), 1115–23.
57
58. De Boer et al. (2006). Evaluation of cross-sectional and longitudinal construct
validity of two vision-related quality of life questionnaires: the LVQOL and VCM1.
Quality of life research, 15(2), 233–48.
Spies-Dorgelo et al.(2006). Reproducibility and responsiveness of the Symptom
Severity Scale and the hand and finger function subscale of the Dutch arthritis
impact measurement scales (Dutch-AIMS2-HFF) in primary care patients with
wrist or hand problems. Health and quality of life outcomes, 4, 87.
Hendriks, E. J. M., Bernards, A. T. M., De Bie, R. A., & De Vet, H. C. W. (2008). The
minimal important change of the PRAFAB questionnaire in women with stress
urinary incontinence: results from a prospective cohort study. Neurourology and
urodynamics, 27(5), 379–87.
Tamber et al. (2009). Measurement properties of the Dizziness Handicap Inventory
by cross-sectional and longitudinal designs. Health and quality of life outcomes,
7, 101.
Van der Velde, G., Beaton, D., Hogg-Johnston, S., Hurwitz, E., & Tennant, A. (2009).
Rasch analysis provides new insights into the measurement properties of the
neck disability index. Arthritis and rheumatism, 61(4), 544–51.
De Vet et al. (2007). Minimally important change determined by a visual method
integrating an anchor-based and a distribution-based approach. Quality of life
research : an international journal of quality of life aspects of treatment, care
and rehabilitation, 16(1), 131–42. 58
参考・引用文献