Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc
Journal website https://jocmr.elmerjournals.com

Original Article

Volume 18, Number 1, January 2026, pages 1-8

Assessment of Social Functioning in Patients With Schizophrenia and Their First-Degree Relatives

Figures

↓  Figure 1. Area under the receiver operating characteristic curve for calculating the cutoff value of SFS for schizophrenia. AUC: area under the curve; SFS: Social Functioning Scale.
Figure 1.
↓  Figure 2. Proportion of subjects with SFS < 140 in each group. ***P < 0.0001 Cochran-Armitage test. There was a significant linear trend in the proportion of SFS < 140 among the three groups. SCZ: schizophrenia; FR: first-degree relatives; HC: healthy controls; SFS: Social Functioning Scale.
Figure 2.
↓  Figure 3. SFS subscales for each group. *P < 0.05, **P < 0.01, ***P < 0.001. HC: healthy controls; FR: first-degree relatives; SCZ: schizophrenia; SFS: Social Functioning Scale.
Figure 3.
↓  Figure 4. The correlation between SFS scores of SCZ patients and their unaffected parents. A total of 22 pairs comprising patients with SCZ and their unaffected parents were included. The Spearman rank correlation coefficient was 0.3963 (P = 0.0679). The gray shaded area represents the 95% confidence interval. SCZ: schizophrenia.
Figure 4.

Tables

↓  Table 1. Subjects Background
 
Total (n = 256) SCZ (n = 44) FR (n = 26) HC (n = 186) P
SCZ: schizophrenia; FR: first-degree relatives; HC: healthy controls; JART: Japan Adult Reading Test, SFS: Social Functioning Scale.
Sex (male), n (%) 96 (37.5%) 17 (38.6%) 6 (23.1%) 73 (39.2%) 0.2761
Age (years), mean ± SD 48.0 ± 16.0 52.7 ± 13.7 68.3 ± 11.1 44.0 ± 14.6 < 0.0001
Educational history (years), mean ± SD 13.5 ± 2.2 12.3 ± 2.0 12.4 ± 1.8 13.9 ± 2.1 < 0.0001
JART50, mean ± SD 106.3 ± 9.2 98.3 ± 11.5 105.0 ± 10.3 108.3 ± 7.2 < 0.0001
SFS total score, mean ± SD 149.2 ± 36.2 90.9 ± 36.5 130.1 ± 24.6 165.7 ± 16.8 < 0.0001

 

↓  Table 2. Effect of Group (SCZ, FR, HC) on SFS Total Score: ANCOVA
 
Estimate SE t value P
Model: P < 0.0001, R2 = 0.700. ANCOVA: analysis of covariance; HC: healthy controls; FR: first-degree relatives; SCZ: schizophrenia; SE: standard error; JART: Japan Adult Reading Test.
Group (HC) 29.71 2.32 12.8 < 0.0001
Group (FR) –1.21 3.25 –0.37 0.711
Group (SCZ) –28.5 2.88 –9.9 < 0.0001
Age –0.12 0.09 –1.25 0.2113
Educational history 1.95 0.66 2.97 0.0033
JART50 0.40 0.18 2.23 0.0269
Sex (male) –3.38 1.34 –2.52 0.0123
Sex (female) 3.38 1.34 2.52 0.0123

 

↓  Table 3. Difference in SFS Total Score Between Groups: Linear Contrast Test Based on ANCOVA
 
Difference in SFS total score ± SE P
ANCOVA: analysis of covariance; SCZ: schizophrenia; FR: first-degree relatives; HC: healthy controls.
Difference between SCZ and FR –27.3 ± 5.7 0.0067
Difference between FR and HC –30.9 ± 4.9 0.0004
Difference between SCZ and HC –58.2 ± 4.1 < 0.0001

 

↓  Table 4. Cutoff Value for SCZ in the SFS Total Score
 
SCZ (n = 44) Other than SCZ (n = 212) Sensitivity Specificity
SCZ: schizophrenia; Other than SCZ: first-degree relatives and healthy controls; SFS: Social Functioning Scale total score.
SFS < 140 42 (95.5%) 32 (15.1%) 0.954 0.849
SFS ≥ 140 2 (4.5%) 180 (84.9%)