Post-concussion symptoms 1-year after traumatic brain injury: using the Rivermead Post-concussion Questionnaire to identify predictors of severity

Figures & data

Figure 1. Study flow diagram.

Table 1. Demographics of study population and univariate analysis (Mann–Whitney) with RPQ at 1 yr.

Variable	Number(%)	Mean Rank	Z-score	p-value
Gender				0.794
Male	779(69%)	567.70	−0.261
Female	352(31%)	562.23
Ethnicity				0.259
White Nonwhite	1043(92%) 88(8%)	562.82	−1.128
Home support				0.865
No Home support	449(40%)	568.03	−0.170
With Home support	682(60%)	564.66
Co-morbidity				0.071
None	842(74%)	576.28	−1.808
Yes Working at the time of injury Yes No Age, mean (SD) Age, median(range) GCS, mean (SD) GCS, median(range) Alcohol Intoxication No Yes	289(26%) 966(85%) 165(15%) 46.9(20.1) 45.5 (17–83) 11.93(3.15) 13 (3–15) 839 (74%) 292 (26%)	536.05 542.37 704.34 530.67 667.52	−5.892 –6.172	0.001** 0.272 0.001** 0.001**

** Indicates significance at p < 0.0001 * Indicates significance at p < 0.05

Table 2. Demographics of study population and univariate analysis (Kruskal–Wallis) with RPQ at 1 yr.

Variable	Number (%)	Mean Rank	p-value
TBI etiology			<0.001**
Fall	369(33%)	519.98
RTC Assault Sports Other	323(28%) 214(19%) 76(7%) 149(13%)	570.13 639.19 427.39 636.60
Socioeconomic status			0.010
Professional Lower Management Intermediate Small employer Lower supervisory Semi-routine Routine Never worked Students	80(7%) 176(15%) 96(8%) 79(7%) 187(17%) 257(23%) 146(13%) 56(5%) 54(5%)	547.89 538.49 565.22 555.98 572.29 585.76 601.69 641.61 407.79
Job at 6 weeks after injury			<0.001**
None Less work Same work	445(39%) 358(32%) 328(29%)	726.34 574.73 338.94
CT Lesion
No abnormality	453(40%)	484.80	<0.001**
Single Lobe Lesion Adjacent Lobes Diffuse Lesions	214(19%) 386(34%) 78(7%)	488.90 658.41 791.81

** Indicates significance at p < 0.0001 * Indicates significance at p < 0.05

Table 3. RPQ (Rivermead Post-concussion Questionnaire) scores at 6 weeks and 1 year.

RPQ score	8 weeks (%)	1 year (%)
Minimal (0–12)	437(38.6)	567(50.1)
Mild (13–24)	333(29.4)	347(30.7)
Moderate (25–31)	186(16.4)	126(11.1)
Severe (>32)	175(15.5)	91(8.0)

Table 4. Multivariate analysis of the Rivermead post-concussion questionnaire using multiple regression.

				95% CI for OR
	B	p-value	OR	Lower	Upper
Ethnicity	0.009	0.740	0.332	−1.876	2.641
Gender	0.044	0.119	1.559	−0.276	2.413
Age at injury	0.044	0.202	1.275	−0.014	0.066
Socioeconomic Class
Professional – baseline	-	-
Lower Manager	−0.027	0.530	−0.628	−3.650	1.787
Intermediate	−0.017	0.643	−0.464	−3.650	2.254
Small Employer	−0.037	0.292	−1.054	−4.751	1.431
Lower Supervisory	−0.034	0.433	−0.784	−3.644	1.564
Semi-routine	−0.056	0.239	−1.179	−4.021	1.003
Routine	−0.023	0.575	−0.562	−3.499	1.942
Never Worked	−0.050	0.166	−1.387	−6.299	1.081
Student	−0.062	0.069	−1.819	−6.797	0.258
Pre-injury work	0.125	0.001**	4.165	2.124	5.909
Home support	0.022	0.417	0.812	−0.714	1.722
Etiology
Assault – baseline	-	-
Fall	−0.116	0.005*	−2.808	−4.768	−0.845
RTC	−0.046	0.227	−1.208	−3.016	0.717
Sports	−0.080	0.010*	−2.582	−6.399	−0.873
Other	−0.015	0.649	−0.455	−2.716	1.693
GCS	−0.149	0.001**	−0.524	−0.733	−0.315
Psychiatric Hx	0.148	0.001**	5.298	2.660	5.788
Comorbidity	−0.083	0.007*	−2.680	−3.735	−0.577
Intoxicated	0.057	0.055	1.920	−0.032	2.970
CT Scan
NAD-baseline	-	-
Mild	−0.056	0.070	−1.814	−3.339	0.131
Moderate	0.082	0.022*	2.302	0.290	3.636
Severe	0.078	0.016*	2.414	0.649	6.282
Return to Work	−0.225	0.001**	−5.210	−6.557	−3.863

GCS; Glasgow coma scale, RTC; Road Traffic Collision. *Denotes p < 0.05 **denotes p < 0.001