Table 2.

Descriptive characteristics and univariate associations with problem behaviour at age 11.

Variable	N (Total = 8499)	% total	N Problem behaviour	% Problem behaviour	N No problem behaviour	% No problem behaviour	p-value
Sociodemographic variables
Age							0.020
10	2800	34.2	246	40.0	2554	33.6
11	5666	65.5	444	59.7	5222	66.1
12	33	0.4	2	0.4	31	0.4
Sex							<0.001
Male	4260	50.9	422	62.9	3838	49.7
Female	4239	49.1	270	37.1	3969	50.3
Ethnicity							0.721
White	7650	90.6	623	91.1	7027	90.6
Non-white	849	9.4	69	8.9	780	9.5
Siblings b							<0.001
0	968	11.6	106	16.0	862	11.1
1	4041	47.3	273	39.0	3768	48.2
2	2381	28.0	184	27.0	2197	28.1
≥3	1109	13.1	129	18.0	980	12.6
Mother’s academic qualification a
Tertiary degree	2599	26.8	109	13.3	2490	28.1
A-levels	926	10.0	56	7.4	870	10.3
GCSE	3994	50.1	391	58.0	3603	49.3
None of these	980	13.1	136	21.3	844	12.3
Mother’s age at child’s birth							<0.001
<20 years	507	7.7	71	12.3	436	7.2
20–24 years	1260	15.9	166	26.3	1094	14.9
25–29 years	2410	29.2	212	31.9	2198	28.9
30–34 years	2797	30.7	161	20.1	2636	31.7
≥35 years	1516	16.6	82	9.4	1434	17.3
Housing tenure b							<0.001
Own/mortgage	6177	67.2	357	44.9	5820	69.4
Council	938	13.3	161	25.1	777	12.1
Rent/other	1384	19.5	174	30.0	1210	18.45
Child health endowment variables
Birthweight							0.015
>2.5 kg	8009	94.2	635	91.2	7374	94.1
≤2.5 kg	490	5.8	57	8.8	433	5.9
Gestational age							0.012
≥37 weeks	7886	92.3	628	88.7	7258	92.6
<37 weeks	613	7.7	64	11.3	549	7.4
Child longstanding illness b							<0.001
No	6928	81.2	462	66.8	6466	82.7
Yes	1571	18.8	230	33.2	1341	17.3
Mother’s alcohol intake during pregnancy							<0.001
Never	5715	66.4	504	71.0	5211	65.9
Light	2164	26.2	124	18.6	2040	26.9
Moderate	449	5.3	45	7.3	404	5.1
Heavy/binge	171	2.1	19	3.1	152	2.0
Mother’s smoking in pregnancy							<0.001
Never smoked	5690	64.5	349	47.9	5341	66.2
Stopped smoking during pregnancy	1076	13.3	93	12.2	983	13.4
Smoked throughout pregnancy	1733	22.2	250	40.0	1483	20.4
Breastfeeding duration							<0.001
No breastfeeding	2482	32.2	248	38.6	2234	31.6
<7 days	979	9.8	107	12.9	872	9.6
1 week to 3 months (inclusive)	2127	24.8	191	29.1	1936	24.4
3 to 6 months (inclusive)	1225	14.0	54	7.9	1171	14.6
>6 months	1686	19.1	92	11.8	1594	19.8
Maternal psychological distress pattern							<0.001
Never	3185	36.3	81	10.9	3104	38.9
Early years only	520	6.1	19	3.0	501	6.4
Middle years only	604	7.2	44	6.5	560	7.24
Age 11 only	637	7.6	48	6.1	589	7.8
Other pattern	1237	14.3	169	23.3	1068	13.4
Recurrent	1930	23.8	243	37.6	1687	22.4
Persistent	386	4.7	88	12.7	298	3.9
Family/External factors variables
Change in mother’s relationship, wave 4–5							0.001
Became single	531	6.4	61	8.1	470	6.22
Became partnered	358	4.8	56	7.9	302	4.4
No change	7610	88.9	575	84.0	7035	89.3
Regular bedtime on weekdays b							0.036
Never/almost never	288	3.4	36	4.8	252	3.2
Sometimes	435	5.0	51	6.9	384	4.9
Usually	2699	31.7	226	31.8	2473	31.7
Always	5077	59.9	379	56.5	4698	60.2
Hours spent playing computer/video games during week b							<0.001
None	866	10.4	91	13.6	775	10.1
<1 hour	4644	53.7	322	44.5	4322	5.5
1–3 hours	2668	32.0	229	34.4	2439	31.8
>3 hours	321	3.9	50	7.5	271	3.52
Mother's satisfaction with time spent with child b							0.001
Enough or more than enough	2029	24.1	195	27.8	1834	23.7
Just enough	3682	43.6	243	35.3	3439	4.4
Not enough	2788	32.3	254	36.9	2534	31.9
Tells off when naughty b							<0.001
Never	48	0.5	1	0.2	47	0.5
Rarely	1019	12.1	51	7.9	968	12.5
Sometimes	3003	35.1	146	20.4	2857	36.6
Often	4429	52.3	494	71.6	3935	50.4
Sends to room when naughty b							<0.001
Never	1037	11.4	39	5.3	998	12.0
Rarely	2498	29.5	126	15.7	2372	15.7
Sometimes	3406	39.5	227	33.3	3179	33.3
Often	1558	19.6	300	45.7	1258	45.7
Takes things away when naughty b							<0.001
Never	687	7.4	39	4.8	648	7.7
Rarely	2414	28.6	109	15.0	2305	29.9
Sometimes	3931	46.1	271	39.2	3660	46.8
Often	1467	17.9	273	41.0	1194	15.5
Amount of time reading to child b							<0.001
Not at all	176	2.0	19	2.2	157	1.9
Approximately monthly	615	7.2	69	12.7	546	6.7
Weekly or more	7708	90.8	604	85.1	7104	91.4
Time spent playing games with child b							<0.001
Not at all	385	4.4	61	7.2	324	4.14
Approximately monthly	2226	26.5	154	22.2	2072	26.9
Weekly or more	5888	69.1	477	70.6	5411	68.9
Mother longstanding health condition b							<0.001
No	6382	75.1	427	61.4	5955	76.4
Yes	2117	24.9	265	38.6	1852	23.6
Mother smoking							<0.001
Non-smoker	6383	73.0	417	57.4	5966	74.6
Smoker	2116	27.0	275	42.6	1841	25.4
Mother’s alcohol intake b							<0.001
5+ weekly	576	7.3	30	4.4	546	7.6
3–4 times weekly	1069	12.7	49	6.2	1020	13.3
1–2 times weekly	2445	28.1	172	23.8	2273	28.6
Monthly	3067	36.8	283	42.0	2784	36.3
Never/almost never	1342	15.2	158	23.7	1184	14.3
Time spent with friends outside school b							<0.001
Not at all	440	5.1	94	13.2	346	4.23
Approximately monthly	1532	19.0	120	18.2	1412	19.0
Regularly, 1–3 times per week	4667	55.7	284	41.7	4383	5.71
Most days	1860	20.3	194	26.9	1666	19.64
Time playing sport b							<0.001
Never/rarely	2334	29.1	313	47.2	2021	27.2
Once per week	2309	26.9	175	25.8	2134	26.9
2–3 times per week	3154	36.2	174	21.9	2980	3.8
≥4 times per week	702	7.8	30	5.1	672	8.1

Note: Unweighted counts and survey-weighted proportions reported; numbers may not add up to 8499 due to individuals with missing information; p-values calculated using chi-square tests

^aInformation from wave 1 (age 9 months)

^bInformation from wave 4 (age 7 years)