Table 4

Estimated effect of heading exposure on neurocognitive performance, mental health and cognitive symptoms

	Frequent versus rare			Moderate versus rare
	MD†	95% CI‡	P value‡	MD†	95% CI‡	P value‡
Computerised tests§
Psychomotor speed	13.768	−2.06 to 30.11	0.086	16.027	1.97 to 31.83	0.041*
Reaction time	−4.374	−15.66 to 5.85	0.431	−1.366	−11.74 to 8.70	0.770
Complex attention	7.607	−2.87 to 18.68	0.157	−0.848	−10.60 to 12.49	0.878
Cognitive flexibility	3.156	−7.83 to 15.93	0.581	−0.818	−12.37 to 13.76	0.914
Processing speed	4.073	−8.37 to 17.84	0.518	6.572	−5.93 to 18.75	0.253
Verbal memory	−9.166	−17.59 to –0.12	0.041*	−3.935	−12.86 to 5.72	0.388
Visual memory	−4.368	−16.66 to 7.84	0.486	−8.435	−21.17 to 4.77	0.197
Pen and paper tests§
Category fluency	0.184	−9.15 to 10.52	0.975	1.662	−9.39 to 13.62	0.770
Digit span	−4.509	−15.98 to 9.43	0.479	−9.247	−22.99 to 3.84	0.124
TMT A	−4.571	−18.12 to 11.56	0.487	−1.824	−12.83 to 10.48	0.750
TMT B	−2.798	−14.92 to 9.63	0.675	−5.304	−16.07 to 7.61	0.356
PASAT	−5.909	−17.13 to 5.11	0.288	−1.946	−13.30 to 9.58	0.741
Cognitive symptoms¶
Sum score**	1.372	−0.51 to 2.95	0.198	0.432	−1.30 to 1.87	0.631
Mental health¶
HADS depression**	1.516	0.11 to 2.92	0.050*	0.203	−0.91 to 1.41	0.746
HADS anxiety**	2.179	0.29 to 3.83	0.030*	1.089	−0.62 to 2.64	0.219
SF36 mental health	−13.203	–19.69 to –6.72	0.001*	−7.286	–14.26 to –0.62	0.028*

*P<0.05.
†Control group as reference.
‡Bias corrected and accelerated based on 1000 bootstrap samples.
§Adjusted for age, education, bodily pain, depression.
¶Adjusted for age, bodily pain.
**Lower scores=better functioning.
HADS, Hospital Anxiety and Depression Scale; MD, mean difference; PASAT, Paced Auditory Serial Addition Test; SF36, SF-36v2 Health Survey; TMT, Trail-Making Test.