In 1997, there were 9,484 traumatic brain injuries or 117.8 per 100,000 population in New Jersey. This number represents an 11.2% decline in the crude rate compared to the baseline year 1994. Overall, there was a 9.5% decrease in the number of TBIs, compared to 1994 (Table 1). While non-fatal TBIs declined 11.2%, fatalities due to TBI increased by 5.1%. Moreover, the decline in the incidence of non-fatal TBIs is completely accounted for by an apparent decrease in the incidence of mild TBIs; rates for both moderate and severe TBIs increased over the same time period (Figure 1.1). Some of the apparent decline in mild TBI is probably caused by restrictions placed on patient stays by Medicare and insurers. A good number of cases that once required hospitalization may now be treated in outpatient departments leading to a decline in the number and rate of mild injuries. Declining numbers of mild and overall rates of TBI-related hospitalizations are also indicated by outside study which concluded that changes in hospital practices may be a major factor in the decreasing rates of TBI-related hospital admissions; these practices increasingly appear to exclude persons with less severe TBI from hospital admission and shift their care to outpatient settings. ⁶

Although the number and rate of TBI incidents decreased in most demographic groups, and from most external causes, there were some exceptions to the general trend: TBI incidence increased among persons 35 through 44 and 85 and over; self-inflicted TBIs increased slightly. The largest decreases in TBI cases occurred in age groups under 35 years, in TBIs from falls (Figures 1.2-1.4).

TABLE 1: NUMBER OF TRAUMATIC BRAIN INJURIES, RATES AND PERCENT CHANGE BY OUTCOME, SEX, AGE, CAUSE, SEVERITY AND RESIDENCE NEW JERSEY, 1994 AND 1997
Category	Number		Rate per 100,000		% change
	1994	1997	1994	1997	Number	Rate
OVERALL	10,479	9,484	132.6	117.8	-9.5%	-11.2%
OUTCOME
Non-fatal	9,400	8,350	118.9	103.7	-11.2%	-12.8%
Fatal	1,079	1,134	13.7	14.1	+5.1%	+2.9%
SEX
Male	6,688	6,101	174.9	156.1	-8.8%	-10.7%
Female	3,791	3,383	92.9	81.6	-10.8%	-12.2%
AGE GROUP
Under 5	724	544	125.1	97.7	-24.9%	-21.9%
5 -14	1,027	787	97.4	70.4	-23.4%	-27.7%
15 - 24	1,973	1,611	200.3	164.5	-18.3%	-17.9%
25 - 34	1,587	1,290	125.5	110.3	-18.7%	-12.1%
35 - 44	1,224	1,316	94.1	95.0	+7.5%	+1.0%
45 - 54	902	878	93.4	83.2	-2.7%	-10.9%
55 - 64	627	631	92.7	92.4	+0.6%	-0.3%
65 - 74	795	766	129.8	128.4	-3.6%	-1.1%
75 - 84	1,042	975	292.4	252.9	-6.4%	-13.5%
85+	578	686	529.1	554.2	+18.7%	+4.7%
CAUSE
Motor vehicle	3,952	3,838	50.0	47.7	-2.9%	-4.6%
Fall	3,772	3,146	47.7	39.1	-16.6%	-18.0%
Other unintentional	1,223	1,136	15.5	14.1	-7.1%	-9.0%
Self-inflicted	194	198	2.5	2.5	+2.1%	0.0%
Assault	1,154	1,114	14.6	13.8	-3.5%	-5.5%
Other	93	43	1.2	0.5	-53.8%	-58.3%
Unknown	91	9	1.2	0.1	-90.1%	-91.7%
INJURY SEVERITY*
Mild	6,619	5,265	83.7	65.4	-20.5%	-21.9%
Moderate	701	781	8.9	9.7	11.4%	9.0%
Severe	1,816	2,138	23.0	26.5	17.7%	15.2%
Unknown	264	166	3.3	2.1	-37.1%	-36.4%
TOTAL	9,400	8,350	118.9	103.7	-11.2%	-12.8%
RESIDENCE
New Jersey	9,941	8,938	125.8	111.0	-10.1%	-11.8%
Out-of-state	380	408	N/A	N/A	+7.4%	N/A
Unknown	158	138	N/A	N/A	-12.7%	N/A
* Includes only non-fatal hospitalizations.

AGE AND SEX As in 1994, nearly two-thirds of the TBI incidents in 1997 in New Jersey occurred among males (Table 2.1). The male age-adjusted TBI rate remained more than twice the female rate. Among TBI victims aged 75 and over, there were substantially more females than males (Figure 2.1). However, the age-specific rates for TBIs, both fatal and non-fatal, were higher for males in every age group (Table 2.2 and Figures 2.2 and 2.3).

TABLE 2.1: NUMBER OF TRAUMATIC BRAIN INJURIES AND RATES BY AGE AND SEX NEW JERSEY, 1997
AGE GROUP	NUMBER			RATE PER 100,000
	MALE	FEMALE	TOTAL	MALE	FEMALE	TOTAL
Under 5	317	227	544	111.3	83.5	97.7
5-14	542	245	787	94.6	44.9	70.4
15-24	1,189	422	1,611	236.6	88.5	164.5
25-44	1,892	714	2,606	149.8	55.3	102.0
45-64	1,034	475	1,509	123.4	52.8	86.8
65-74	427	339	766	162.9	101.4	128.4
75-84	450	525	975	301.1	222.4	252.9
85+	250	436	686	718.9	489.9	554.2
TOTAL	6,101	3,383	9,484	156.1	81.6	117.8
Percent	64.3%	35.7%	100.0%
Age-adjusted rate based on all occurrences-1997				153.2	67.9	110.2
1994				174.8	81.6	127.7
% change 1994-1997				-12.4%	-16.8%	-13.7%
Age-adjusted rate based on resident occurrences-1997				144.1	63.9	103.7
1994				165.1	77.8	121.0
% change 1994-1997				-12.7%	-17.9%	-14.3%

TABLE 2.2: NUMBER OF TRAUMATIC BRAIN INJURIES AND RATES BY AGE, OUTCOME AND SEX NEW JERSEY, 1997
	FATAL
AGE GROUP	NUMBER			RATE PER 100,000
	MALE	FEMALE	TOTAL	MALE	FEMALE	TOTAL
Under 5	11	10	21	3.9	3.7	3.8
5-14	24	10	34	4.2	1.8	3.0
15-24	122	39	161	24.3	8.2	16.4
25-44	207	62	269	16.4	4.8	10.5
45-64	166	47	213	19.8	5.2	12.3
65-74	81	36	117	30.9	10.8	19.6
75-84	109	77	186	72.9	32.6	48.2
85+	59	74	133	169.7	83.1	107.5
TOTAL	779	355	1,134	19.9	8.6	14.1
Percent	68.7%	31.3%	100.0%
Age-adjusted based on all occurrences-1997				17.6	5.9	11.5
1994				17.8	5.5	11.3
% change 1994-1997				-1.1%	+7.3%	+1.8%
Age-adjusted rate for New Jersey resident population-1997				16.7	5.6	11.0
1994				16.3	5.0	10.3
% change 1994-1997				+2.5%	+12.0%	+6.8%
	NON-FATAL
AGE GROUP	NUMBER			RATE PER 100,000
	MALE	FEMALE	TOTAL	MALE	FEMALE	TOTAL
Under 5	306	217	523	107.4	79.8	93.9
5-14	518	235	753	90.4	43.1	67.3
15-24	1,067	383	1,450	212.4	80.3	148.1
25-44	1,685	652	2,337	133.4	50.5	91.5
45-64	868	428	1,296	103.6	47.5	74.6
65-74	346	303	649	132.0	90.6	108.8
75-84	341	448	789	228.2	189.8	204.7
85+	191	362	553	549.3	406.7	446.8
TOTAL	5,322	3,028	8,350	136.2	73.1	103.7
Percent	63.7%	36.3%	100.0%
Age-adjusted rate based on New Jersey occurrences - 1997				135.6	62.0	98.6
1994				157.0	76.1	116.4
% change				-13.6%	-18.5%	-15.3%
Age-adjusted rate for New Jersey resident population - 1997				127.4	58.3	92.7
1994				148.8	72.8	110.7
% change 1994-1997				-14.4%	-19.9%	-16.3%

AGE, SEVERITY AND OUTCOME More than half of the TBIs in New Jersey were mild non-fatal and fewer than 10% were of non-fatal moderate severity (Table 1 and Table 2.3). The greatest frequency of non-fatal mild and moderate TBIs occurred among persons 15 through 44 years of age. More than 20% of the TBIs were severe but not fatal. The higher rates for these cases by far were in the 75 and over population. Half of the hospitalized fatalities related to TBI were of persons 65 and over, whereas this group accounted for only 29% of the non-hospitalized fatalities. The highest rates of TBI regardless of severity were in the population 85 and over (Table 2.3 and Figure 2.4). Rates in all of these categories were particularly high in persons 75 through 84 years also. Other than the elderly population (65 years and over), the highest rates in each severity and fatality site were in the young population, 15 through 24 years, and this group had the second highest rate of mild TBIs. Of TBIs occurring in females, the percent that were mild was somewhat higher than the percent of TBIs that were mild in males, even though the number of TBIs and total in males was higher than in females (Figure 2.5).

TABLE 2.3: NUMBER OF TRAUMATIC BRAIN INJURIES AND RATES BY AGE, OUTCOME AND SEVERITY NEW JERSEY, 1997
AGE GROUP	NON-FATAL			FATAL		TOTAL
	MILD	MODER- ATE	SEVERE	HOSPI- TALIZED	NON- HOSPI- TALIZED
Under 5	316	56	139	14	7	544
5-14	537	67	130	17	17	787
15-24	1,030	129	273	54	107	1,611
25-44	1,569	232	496	87	182	2,606
45-64	811	116	350	78	135	1,509
65-74	349	71	217	60	57	766
75-84	378	69	322	109	77	975
85+	275	41	211	80	53	686
TOTAL	5,265	781	2,138	499	635	9,484
Percent	55.5%	8.2%	22.5%	5.3%	6.7%	100.0%
AGE GROUP	NON-FATAL RATE PER 100,000			FATAL RATE PER 100,000		TOTAL RATE PER 100,000
	MILD	MODER- ATE	SEVERE	HOSPI- TALIZED	NON- HOSPI- TALIZED
Under 5	56.7	10.1	25.0	2.5	1.3	97.7
5-14	48.0	6.0	11.6	1.5	1.5	70.4
15-24	105.2	13.2	27.9	5.5	10.9	164.5
25-44	61.4	9.1	19.4	3.4	7.1	102.0
45-64	46.7	6.7	20.1	4.5	7.8	86.8
65-74	58.5	11.9	36.4	10.1	9.6	128.4
75-84	98.1	17.9	83.5	28.3	20.0	252.9
85+	222.2	33.1	170.5	64.6	42.8	554.2
TOTAL	65.4	9.7	26.5	6.2	7.9	117.8
Note 1.Mild (ICD/AIS=1 or 2) 2.Moderate (ICD/AIS = 3) 3.Severe (ICD/AIS= 4 - 6) 4.Total includes unknown levels of severity

AGE, OUTCOME AND CAUSE The major external causes of TBI in 1997 in New Jersey were motor vehicle injuries and falls (Table 3A). The largest numbers of motor vehicle-related fatalities and non-fatal TBI incidents occurred among the population 15 through 44 years. The greatest frequencies of TBIs from falls were in the population 75 and over. Self-inflicted TBIs were highest in 25 through 64 year olds and TBIs from assaults occurred in highest numbers among 15 though 44 year olds (Table 3A). Despite the higher number of TBI-related fatalities from motor vehicle-related causes in the younger population, the rates of these fatalities were highest in the ages 75 and over population, as were TBI fatalities from falls, other unintentional causes and self-inflicted injuries (Table 3B and Figure 3). The rate of self-inflicted TBI-related fatalities in the 45-64 years was also relatively high, and the assault rate in 15 through 24 year olds was higher than in any other age group. Rates of non-fatal TBIs related to the use of motor vehicles were much higher among persons aged 15 through 24 year olds than among other age groups. The rate of non-fatal TBI caused by assault was also substantially elevated among adolescents and young adults. Persons 75 and over had the highest rates of non-fatal TBI from falls and other unintentional injuries, and had the highest non-fatal TBI rates from all causes (Table 3B).

TABLE 3A: TRAUMATIC BRAIN INJURIES BY AGE, OUTCOME AND CAUSE NEW JERSEY, 1997
FATAL
Age group	Motor Vehicle	Fall	Other uninten- tional	Self inflicted	Assault	Other/ Unknown	All Causes
Under 5	11	2	5	0	3	0	21
5 -14	21	4	4	0	4	1	34
15 - 24	80	5	12	17	43	4	161
25 - 44	99	23	36	51	57	3	269
45 - 64	56	49	23	59	23	3	213
65 - 74	27	50	21	14	4	1	117
75 - 84	35	83	48	17	1	2	186
85 +	20	69	37	4	3	0	133
TOTAL	349	285	186	162	138	14	1,134
PERCENT	30.8%	25.1%	16.4%	14.3%	12.2%	1.2%	100.0%
NON-FATAL
Age group	Motor Vehicle	Fall	Other uninten- tional	Self inflicted	Assault	Other/ Unknown	All Causes
Under 5	86	349	53	0	30	5	523
5 -14	303	215	193	2	38	2	753
15 - 24	868	165	173	7	234	3	1,450
25 - 44	1,190	387	218	17	510	15	2,337
4