Measuring job stress in transportation workers: psychometric properties, convergent validity and reliability of the ERI and JCQ among professional drivers

Table 5 JCQ-20 factor scoring parameters and variable ranges

Variable/factor	No.	Number of items	Items /factors involved	Calculation formula	Range
Root Factors
Skill Discretion	F1	4	1,2,5,7	((JCQ1 + JCQ2 + JCQ5 + JCQ7)*3)	[12–48]
Decision Authority	F2	3	3,4,6	((JCQ3 + JCQ4 + JCQ6)*4)	[12–48]
Psychological Demands	F3	5	8,9,10,11,12	((JCQ8 + JCQ9)3) + ((JCQ10 + JCQ12)3) + ((5-JCQ11)*2)^a	[12–48]
Supervisor Support	F4	4	13,14,15,16	(JCQ13 + JCQ14 + JCQ15 + JCQ16)	[4–16]
Co-worker Support	F5	4	17,18,19,20	(JCQ17 + JCQ18 + JCQ19 + JCQ20)	[4–16]
Composed Factors^b
Control	F6	7	F1,F2	F1 + F2	[24–96]
Social Support	F7	8	F4,F5	F4 + F5	[8–32]
Job Strain (JS) Indicator^c
Job Strain	F8	12	F3,F6	(F3*2)/F6	–

Notes: ^aAssuming that the negative item (JCQ11, measured in a 1–4 scale) has not been previously reversed; ^bCan be understood as the sum of previously calculated factors with acceptable psychometric properties; ^cA resulting value higher than 1.0 indicates imbalance between Demands and Control, or Job Strain

ISSN: 1471-2458