Psychological distress in Spanish airline pilots during the aviation crisis caused by the COVID-19 pandemic and psychometric analysis of the 12-item general health questionnaire

Figures & data

Table 1. Characteristics of the sample by age and employment status, and mean scores and standard deviation for standard GHQ score, for the complete sample and for each age group and employment status.

Variable	Category	Total (N)	(%)	Standard GHQ score (mean ± SD)
Age group	≤30	19	5.5	5.98 ± 3.77
	31–40	65	19.0	5.15 ± 3.01
	41–50	155	45.2	4.17 ± 3.21
	51–60	96	28.0	4.42 ± 3.45
	≥61	7	2.0	4.86 ± 3.94
Employment situation	Unemployed	32	9.4	6.00 ± 3.61
	On furlough	226	66,1	4.85 ± 3.34
	Working normally	84	24.6	3.13 ± 2.60
Total	Total	342	100	4.54 ± 3.31

Figure 1. Total GHQ-12 score according to employment status.

The highest General Health Questionnaire-12 score (6 points) corresponds to unemployed pilots. It is intermediate for those on furlough (4.8 points) and lower (3 points) for those who work normally.

Figure 2. Percentages on each item in the GHQ-12 according to the employment status of the pilots in the sample.

A histogram compares one by one the answers to the 12 questions of the General Health Questionnaire as a function of employment status. The largest differences corresponded to items 3, 4, 5, 6, 8, 10, 11, and 12. In all of them, the highest percentages of favourable (or healthy) responses corresponded to pilots working. The lowest percentage of favourable responses always corresponded to unemployed subjects.

Table 2. Comparison of percentages between different pairs of groups according to employment status (Unemployed/Working; Unemployed/Furloughed; Working/Furloughed) for each item on the questionnaire, referring to the proportion of individuals that obtained 1 point for each item.

Items	Unemployed	Working	p-value	Unemployed	On furlough	p-value	Working	On furlough	p-value
	(%)	(%)		(%)	(%)		(%)	(%)
Have you been able to concentrate on what you were doing? GHQ1	56.2	44.0	NS	56.2	56.6	NS	44.0	56.6	NS
			p = 0.166			p = 0.557			p = 0.032
Have you lost much sleep over worry? GHQ2	62.5	60.7	NS	62.5	64.2	NS	60.7	64.2	NS
			p = 0.518			p = 0.5			p = 0.333
Have you felt you were playing a useful part in things? GHQ3	46.9	8.3	p ≤ 0.001	46.9	34.5	NS	8.3	34.5	p ≤ 0.001
						p = 0.122
Have you felt capable of making decisions about things? GHQ4	34.4	10.7	NS	34.4	21.7	NS	10.7	21.7	NS
			p = 0.004			p = 0.089			p = 0.018
Have you felt constantly under strain? GHQ5	84.4	47.6	p ≤ 0.001	84.4	68.1	NS	47.6	68.1	p ≤ 0.001
						p = 0.042
Have you felt you could not overcome your difficulties? GHQ6	43.8	9.5	p ≤ 0.001	43.8	28.8	NS	9.5	28.8	p ≤ 0.001
						p = 0.067
Have you been able to enjoy normal day to day activities? GHQ7	59.4	57.1	NS	59.4	53.5	NS	57.1	53.5	NS
			p = 0.499			p = 0.335			p = 0.331
Have you been able to face up to your problems? GHQ8	34.4	13.1	NS	34.4	27.4	NS	13.1	27.4	NS
			p = 0.011			p = 0.268			p = 0.005
Have you been feeling unhappy and depressed? GHQ9	62.5	31.0	NS	62.5	62.4	NS	31.0	62.4	p ≤ 0.001
			p = 0.002			p = 0.577
Have you been losing confidence in yourself? GHQ10	40.6	7.1	p ≤ 0.001	40.6	20.4	NS	7.1	20.4	NS
						p = 0.013			p = 0.003
Have you been thinking of yourself as a worthless person?GHQ11	18.8	1.2	NS	18.8	8.4	NS	1.2	8.4	NS p = 0.013
			p = 0.002			p = 0.070
Have you been feeling reasonably happy, all things considered?GHQ12	56.2	22.6	p ≤ 0.001	56.2	38.9	NS	22.6	38.9	NS
						p = 0.048			p = 0.005
Total	62.5	25.0	p ≤ 0.001	62.5	47.3	NS	25.0	47.3	p ≤ 0.001
						p = 0.078

The significance values are also shown in bold**. ^**p ≤ 0.001.

NS: Non-significant.

Table 3. Reliability analysis. Cronbach’s alpha if each item is deleted, item-total correlation across the 12 items on the GHQ-12 questionnaire and Cronbach’s alpha for the sample and subgroups.

Sample	Total		Unemployed		On furlough		Working
Item	Cronbach alpha if item is deleted	Corrected item-total correlation	Cronbach alpha if item is deleted	Corrected item-total correlation	Cronbach alpha if item is deleted	Corrected item-total correlation	Cronbach alpha if item is deleted	Corrected item-total correlation
GHQ1	0.845	0.444	0.861	0.360	0.845	0.448	0.779	0.449
GHQ2	0.846	0.426	0.861	0.356	0.846	0.425	0.766	0.548
GHQ3	0.843	0.460	0.855	0.456	0.847	0.415	0.779	0.452
GHQ4	0.836	0.567	0.846	0.582	0.835	0.575	0.780	0.423
GHQ5	0.836	0.568	0.853	0.480	0.836	0.557	0.764	0.566
GHQ6	0.827	0.686	0.835	0.737	0.827	0.687	0.774	0.515
GHQ7	0.845	0.448	0.846	0.574	0.840	0.502	0.794	0.325
GHQ8	0.833	0.613	0.840	0.670	0.833	0.603	0.771	0.533
GHQ9	0.835	0.576	0.839	0.674	0.837	0.547	0.769	0.520
GHQ10	0.837	0.560	0.848	0.552	0.836	0.567	0.784	0.386
GHQ11	0.849	0.373	0.862	0.308	0.848	0.374	0.794	0.297
GHQ12	0.835	0.574	0.838	0.693	0.835	0.573	0.783	0.391
Total Cronbach’s alpha	0.851		0.860		0.850		0.793

Table 4. Item and psychometric properties of the GHQ-12.

Item	Factor loading*	Mean	Confidence interval (95%)	Skewness	Kurtosis
GHQ1	0.588	0.535	0.47–0.60	–0.141	–1.977
GHQ2	0.579	0.632	0.56–0.70	–0.547	–1.699
GHQ3	0.665	0.292	0.23–0.36	0.915	–1.161
GHQ4	0.804	0.202	0.15–0.26	1.491	0.219
GHQ5	0.743	0.646	0.58–0.71	–0.613	–1.622
GHQ6	0.950	0.254	0.19–0.31	1.131	–0721
GHQ7	0.606	0.550	0.48–0.62	–0.200	–1.957
GHQ8	0.839	0.246	0.19–0.31	1.185	–0.596
GHQ9	0.794	0.547	0.48–0.62	–0.189	–1.962
GHQ10	0.829	0.190	0.14–0.24	1.585	0.506
GHQ11	0.711	0.076	0.04–0.11	3.209	8.269
GHQ12	0.768	0.365	0.30–0.43	0.560	–1.684

*Extraction method: Factor loadings using the extraction method: unweighted least squares.