Primary mental healthcare for adults with mild intellectual disabilities: a Dutch database study

Figures & data

Figure 1. Composition of groups.

NIVEL-PCD: Netherlands Institute for Health Services Research Primary Care Database; SN: Statistics Netherlands; MID: Group with mild intellectual disability; No-ID: Group with no-intellectual disability; MH: people who had one or more MH problems coded with an ICPC-P other than P85; Match: Match control group; MID-MH: Group with mild intellectual disability and a mental health problem; Match-MH: Match control group with MH problem.

Table 1. Demographics.

		MID	Without ID
Total N		11,887	1,464,196
Men, N (%)		7338 (61.7)**^a	714,136 (48.8)
Age, M (SD)		37.8 (15.0)**	49.4 (17.8)
Age groups, N (%)	18–24	3280 (27.6)**^b	133,518 (9.1)
	25–34	2704 (22.7)	228,303 (15.6)
	35–44	1673 (14.1)	235,777 (16.1)
	45–54	2150 (18.1)	290,016 (19.8)
	55–64	1555 (13.1)	250,964 (17.1)
	65–74	525 (4.4)	325,618 (22.3)
Years registered in database, M (SD)		2.70 (1.15)*	2.76 (1.15)
ICPC P85 Mental retardation, N (%)		2339 (19.7)	n.a.

MID: Mild intellectual disability; ID: intellectual disability; ICPC: International Classification of Primary Care; **p < .001, ^aMID compared with No-ID; ^bage group distribution MID compared with No-ID.

Table 2. Prevalence of mental health problems in persons with and without intellectual disability.

			MID N = 11,887	Without ID N = 1,464,196	OR (95%CI)^b
MH problems (ICPC P1–P99)
≥1 MH problem	N (%)	Total	5808 (48,9)	444,520 (30.4)	2.50 (2.41–2.59)**
		Men^a	3.373 (46.0)	186,985 (26.2)	2.55 (2.43–2.67)**
		Women^a	2435 (53.5)	257,535 (34.3)	2.43 (2.29–2.58)**
	Age		37.1 (14.3)**	50.6 (18.4)
	Median unique MH problems (25–75 percentile)		2.0 (1.0–3.0)**	1.0 (1.0–3.0)
MH complaint (ICPC P1–P29)
≥1 MH complaint	N (%)		4299 (36.2)	313,200 (21.4)	2.39 (2.30–2.49)**
	Median unique MH complaints (25–75 percentile)		1.0 (1.0–2.0)**	1.0 (1.0–1.0)
ICPC code^c N (%)	P28 Limited function/disability		303 (2.5)	1018 (0.1)	38.18 (33.34–43.72)**
	P24 Specific learning problem		116 (1.0)	1,424 (0.1)	6.23 (5.14–7.55)**
	P23 Adolescent behaviour symptom/complaint		96 (0.8)	2362 (0.2)	3.51 (2.86–4.32)**
	P04 Feeling/behaving irritably/angry		224 (1.9)	7809 (0.5)	3.47 (3.03–3.97)**
	P18 Medication abuse		101 (0.8)	5967 (0.4)	3.44 (2.82–4.20)**
	P15–P19 Substance abuse, any form		1,549 (13.0)	76,177 (5.2)	2.64 (2.50–2.79)**
MH disorders (ICPC P70–P99)
≥1 MH disorders	N (%)		3,006 (25.3)	220,298 (15.0)	2.09 (2.00–2.18)**
	Median unique MH disorders (25–75 percentile)		1.0 (1.0–1.0)**	1.0 (1.0–1.0)
ICPC code^c N (%)	P98 Psychosis NOS/other		242 (2.0)	5082 (0.3)	6.07 (5.32–6.92)**
	P71 Organic psychosis other		59 (0.5)	6858 (0.5)	4.43 (3.41–5.75)**
	P99 Psychological disorders, other		566 (4.8)	14,310 (1.0)	3.83 (3.51–4.18)**
	P77 Suicide/suicide attempt		110 (0.9)	3318 (0.2)	3.80 (3.14–4.60)**
	P72 Schizophrenia		158 (1.3)	5348 (0.4)	3.36 (2.87–3.95)**
	P71–73 and/or P98 Psychosis, any form		500 (4.2)	20,645 (1.4)	4.37 (3.99–4.79)**

MID: mild intellectual disability; ID: intellectual disability; MH: Mental health; ICPC: International Classification of Primary Care.

**p < .001, MID compared with No-ID; ^apercentage of the total number of men/women within the group; ^bOR adjusted for age, sex, and years registered in the database; ^cOverview of the 5 ICPC codes of MH complaints/disorders with the highest odds and combined related codes.

Table 3. Consultations with general practitioners and mental health nurse practitioners.

			MID-MH N = 5808	Match-MH^b N = 32,232	OR (95%CI)^c
GP consultations
People with ≥1 consultation during research period, N (%)		Total	5702 (98.2)	22,708 (97.7)	1.29 (1.04–1.60)**
		Men^a	3283 (97.3)	13,070 (96.9)	1.22 (0.97–1.54)
		Women^a	2419 (99.3)	9638 (99.0)	1.67 (0.98–2.83)
Median consultations per year (25–75 percentile)		Total	6.4 (3.3–11.5)**	4.0 (2.0–7.3)
		Men	5.0 (2.5–8.8)**	3.3 (1.7–5.8)
		Women	9.0 (5.0–15.2)**	5.5 (3.0–9.0)
Type of consultation^x	Total (N)		141,267	357,841
	Short consultation, N (%)		66,173 (46.8)	163,943 (45.8)	1.05 (1.03–1.06)**
	Long consultation, N (%)		21,052 (14.9)	60,504 (16.9)	0.86 (0.85–0.88)**
	Home visit short, N (%)		1626 (1.2)	2002 (0.6)	2.12 (1.98–2.26)**
	Home visit long, N (%)		1255 (0.9)	2571 (0.7)	1.25 (1.16–1.33)**
	Consultation by phone, N (%)		50,680 (35.9)	125,560 (35.1)	1.03 (1.02–1.05)**
	E-mail consultation, N (%)		481 (0.3)	3261 (0.9)	0.37 (0.34–0.41)**
MHNP consultations
People with ≥1 consultation during research period, N (%)		Total	1442 (24.8)	6195 (26.7)	0.91 (0.85–0.98)*
		Men^a	710 (21.0)	3130 (23.2)	0.89 (0.81–0.97)*
		Women^a	732 (30.1)	3065 (31.5)	0.94 (0.85–1.04)
Median consultation per year (25–75 percentile) in people ≥1 consultation in research period		Total	1.5 (0.8–3.3)	1.3 (0.7–2.7)
		Men	1.3 (0.7–2.8)	1.3 (0.7–2.4)
		Women	1.5 (0.8–4.0)	1.5 (0.8–3.0)
Type of consultation^d	Total (N)		11,249	36,125
	Short consultation, N (%)		274 (2.4)	564 (1.6)	1.62 (1.40–1.88)**
	Long consultation, N (%)		8586 (76.3)	30,711 (85.0)	0.57 (0.54–0.60)**
	Short home visit short, N (%)		15 (0.1)	17 (0.0)	not applicable
	Long home visit, N (%)		288 (2.6)	204 (0.6)	4.16 (3.46–5.00)**
	Consultation by phone, N (%)		1994 (17.7)	3949 (10.9)	1.77 (1.67–1.88)**
	E-mail consultation, N (%)		91 (0.8)	572 (1.6)	0.53 (0.42–0.66)**
	Group consultations, N (%)		<10^e	108 (0.3)	not applicable

MID-MH: Group with mild intellectual disability and a mental health problem; Match-MH: Match control group with MH problem; GP: General practitioner; MHNP: Mental health nurse practitioner; **p < .001, *p < .05, MID compared with No-ID; ^apercentage of the total number of men/women within the group; ^bMatch-MH: each individual from the MID-MH group randomly matched by age, sex, and number of years in the dataset to four individuals in the No-ID group; ^cOR calculated for variable with an absolute number of ≥ 30 people in one of the groups, adjusted for age, sex, and years registered in the database; ^dLong = >20 min, short = <20 min, percentage of total number of consultations; ^eAbsolute numbers below 10 may are not displayed.

Table 4. Medication prescriptions.

	MID-MH N = 5808	Match-MH N = 23,232	OR (95%CI)^a
All medication
≥1 prescription during research period, N (%)	5450 (93.8)	21,452 (92.3)	1.31 (1.16–1.48)**
Median types prescriptions per year (25–75 percentile)	2.7 (1.3–4.5)**	2.0 (1.0–3.3)
Psychotropics
≥1 prescription during research period, N (%)	3271 (55.4)	11,072 (47.7)	1.39 (1.31–1.47)**
Median types prescriptions per year in people ≥1 psychotropic prescription in research period (25–75 percentile)	0.5 (0.3–1.0)**	0.5 (0.3–1.0)
N05A Antipsychotics, N (%)	1158 (19.9)	1716 (7.3)	3.15 (2.90–3.41)**
N05B Anxiolytics, N (%)	1,446 (24.9)	4473 (19.3)	1.41 (1.32–1.51)**
N05C Hypnotics and sedatives, N (%)	949 (16.3)	3603 (15.5)	1.07 (0.99–1.16)
N06A Antidepressant, N (%)	1,459 (25.1)	5,096 (21.9)	1.20 (1.12–1.29)**
N06B Psychostimulants, N (%)	275 (4.7)	1177 (5.1)	0.93 (0.81–1.07)
N06D Anti-dementia drugs, N (%)	<10^b	23 (0.1)	not applicable
N07B Drugs used in addictive disorders, N (%)	385 (6.6)	1150 (5.0)	1.38 (1.22–1.55)**
Anti-epileptics
≥1 anti-epileptic N03A prescription during research period, N (%)	504 (8.7)	1048 (4.5)	2.05 (1.83–2.29)**

MID-MH: Group with mild intellectual disability and a mental health problem; Match-MH: Match control group with MH problem.

**p < .001, MID compared with No-ID; ^aOR calculated for variable with an absolute number of ≥ 30 people in one of the groups, adjusted for age, sex, and years registered in the database; ^bAbsolute numbers below 10 may are not displayed.

Data availability statement

Aggregated data from the databases used in this study are publicly available on a dedicated website of Statistics Netherlands (http://statline.cbs.nl), and Netherlands Institute for Health Services Research (https://www.nivel.nl/en/nivel-zorgregistraties-eerste-lijn/nivel-primary-care-database). The non-public microdata used to link databases is, under certain conditions, accessible for statistical and scientific research (fees apply). Procedures can be found at www.cbs.nl and www.nivel.nl. For further information: [email protected] and [email protected]