Attention deficit hyperactivity disorder and gastrointestinal morbidity in a large cohort of young adults

Table 1 Sociodemographic characteristics of young adults with and without attention deficit hyperactivity disorder

		ADHD
		No	Yes
	Number of participants	355652	33380
Gender	Female	41.10%	43.30%
	Male	58.90%	56.70%
Socioeconomic status	Low	26.30%	14.70%
	Medium	53.30%	50.30%
	High	20.40%	35.00%
Education	12	94.20%	93.20%
	< 12	0.30%	0.10%
	> 12	5.50%	6.70%
Comorbidities	None or mild	68.10%	63.20%
	Mild to moderate	9.20%	9.80%
	Moderate to severe	22.60%	27.00%
Country of origin	Western countries	21.80%	25.30%
	Africa	23.00%	21.70%
	Asia	20.40%	25.50%
	Former Soviet Union	20.00%	13.00%
	Ethiopia	3.50%	1.10%
	Other	0.50%	0.60%
	Israel	10.80%	12.70%
BMI, mean ± SD	Males	21.93 ± 0.02	22.42 ± 0.06
	Females	21.52 ± 0.02	21.88 ± 0.07
Height in cm, mean ± SD	Males	174.2 ± 0.03	174.4 ± 0.10
	Females	162.2 ± 0.03	162.2 ± 0.10

ADHD: Attention deficit hyperactivity disorder; BMI: Body mass index.

Table 2 Results of logistic regression of the association of attention deficit hyperactivity disorder with gastrointestinal pathology and impact of gastrointestinal morbidity on use of healthcare resources

		Univariate model			Multivariate model
	Methylphenidate	OR	95%CI	P value	RR	95%CI	P value
Celiac	+	0.66	0.25-1.77	0.539
	-	1.08	0.81-1.45	0.592
IBD	+	0.65	0.32-1.30	0.252
	-	1.01	0.82-1.25	0.919
IBS	+	1.63	1.35-1.98	C0.001	1.02	0.81-1.30	0.842
	-	1.67	1.54-1.80	< 0.001	1.29	1.18-1.41	< 0.001
Constipation	+	2.12	1.66-2.69	< 0.001	1.6	1.21-2.13	0.001
	-	1.56	1.40-1.74	< 0.001	1.43	1.26-1.62	< 0.001
Dyspepsia	+	2.03	1.77-2.32	< 0.001	1.75	1.49-2.06	< 0.001
	-	1.4	1.31-1.49	< 0.001	1.2	1.11-1.29	< 0.001
Total complaints	+	1.82	1.55-2.12	< 0.001	1.85	1.56-2.18	< 0.001
	-	1.26	1.17-1.35	< 0.001	1.26	1.17-1.36	< 0.001
Gastroenterologist referrals	+	2.34	2.14-2.57	< 0.001	2.29	2.07-2.53	< 0.001
	-	1.98	1.90-2.06	< 0.001	1.99	1.90-2.07	< 0.001
Visits in a primary care clinic	+	1.53	1.50-1.57	< 0.001	1.56	1.52-1.59	< 0.001
	-	1.23	1.22-1.24	< 0.001	1.23	1.22-1.24	< 0.001

CI: Confidence interval; IBD: Inflammatory bowel disease; IBS: Irritable bowel syndrome; OR: Odds ratio; RR: Rate ratio.

Table 3 Association of attention deficit hyperactivity disorder and reason for referrals to a gastrointestinal specialist by specific symptom

Gastroenterologist referrals	Gastrointestinal symptom	RR	95%CI	P value
	Perianal symptoms	1.69	1.32-2.15	< 0.001
	Heartburn and GERD	2.15	1.88-2.45	< 0.001
	Bowel habit changes	2.04	1.36-3.06	0.001
	Nausea and vomiting	2.53	2.21-2.89	< 0.001
	Weight loss	1.88	1.34-2.64	< 0.001
	Abdominal pain	1.94	1.84-2.04	< 0.001
	Rectal bleeding and melena	1.62	1.39-1.89	< 0.001
	Abdominal gas and bloating	1.58	1.13-2.22	0.008
	Diarrhea	2.05	1.88-2.23	< 0.001
	Abdominal mass	0.98	0.30-3.24	0.973
	Others	2.72	1.56-4.77	< 0.001
	Overall	1.96	1.88-2.03	< 0.001

CI: Confidence intervals; GERD: Gastroesophageal reflux disease; OR: Odds ratio; RR: Rate ratio.