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Table 2 Internal consistency reliability and construct (convergent/divergent, clinical) validity of the FACT-M in the MCC population (n = 172)

From: Update on the psychometric properties and minimal important difference (MID) thresholds of the FACT-M questionnaire for use in treatment-naïve and previously treated patients with metastatic Merkel cell carcinoma

FACT-M subscale, summary and MCC-specific scores# itemsCronbach’s alpha[a]McDonald’s coefficient omegaScale structureECOG PS (mean [SD])
Range of item-subscale correlations[b]Convergent[c]/ divergent[d] validity (% of items)0 (n = 106)1 (N = 66)p-value[e]
FACT-G subscales
 Physical well-being70.840.850.53–0.71100 / 5724.0 (4.2)21.3 (5.6)<.001
 Social/Family well-being[f]60.830.850.55–0.70100 / 10022.5 (5.4)21.6 (5.7)0.308
 Emotional well-being60.800.800.36–0.7083 / 6718.1 (4.1)16.8 (5.0)0.0499
 Functional well-being70.890.890.52–0.77100 / 7118.1 (6.7)15.8 (6.4)0.028
Melanoma-specific subscales
 Melanoma subscale160.840.860.19–0.7650 / 3854.3 (7.5)50.6 (9.0)0.004
 Melanoma surgery scale80.820.830.20–0.7775 / 7527.0 (5.3)24.4 (7.1)0.007
Summary scales
 FACT-M TOI300.9496.4 (16.7)88.1 (19.5)0.003
 FACT-G Total score270.9382.8 (16.2)75.5 (18.1)0.007
 FACT-M Total score430.95137.0 (22.3)126.6 (25.8)0.006
MCC-Specific scores
 Physical function score (PF)60.890.890.61–0.76100 / 10017.2 (5.5)14.3 (5.9)0.001
 Psychological impact score (PI)60.840.850.55–0.72100 / 10018.4 (4.3)17.0 (5.2)0.064
 MCC summary score120.9035.5 (8.7)31.3 (10.0)0.004
  1. # = number; ECOG PS = Eastern Cooperative Oncology Group performance score (0 = fully active; 1 = restricted in physically strenuous activity); MCC = Merkel cell carcinoma; SD = Standard deviation, TOI = Trial Outcome Index
  2. [a] Recommended threshold α > 0.7; [b] Pearson correlation coefficients; [c] % of items correlated with its own dimension ≥0.4; [d] % of items correlated with its own dimension higher that the correlation with any other dimension; [e] p-value from t-test of score between the two ECOG performance status groups at baseline; [f] convergent and divergent validity were calculated without the ‘satisfaction with sex life’ item due to high item missingness resulting from response to this item being voluntary