human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Study Design . A prospect i ve 10-year follow-up study of patients with whiplash-associated disorders ( WAD ) and asymptomatic volunteers . Objective . To clarify long-term impact of whiplash injury on patient 's symptoms and on magnetic resonance imaging ( MRI ) findings of the cervical spine . Summary of Background Data . Long-term prognosis of WAD has not been fully eluci date d. Methods . Between 1993 and 1996 , we conducted cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers , all of whom underwent MRI of the cervical spine .  For this follow-up study , 133 WAD patients and 223 control subjects were recruited again . All participants underwent follow-up MRI and physical examination , and answered to question naires regarding neck symptoms . Evaluation of MRI included decrease in signal intensity of discs , posterior disc protrusion , disc space narrowing , and foraminal stenosis using 2 to 4 numerical grade s. Increase in the numerical grade s by one or more was considered to be progression of degenerative changes . Results . Progression of decrease in signal intensity was observed in 109 WAD patients ( 82.0 % ) , and 132 control subjects ( 59.2 % ) , ( age , sex adjusted odds ratio [ OR ] : 3.06 ) , posterior disc protrusion in 101 ( 75.9 % ) and in 155 ( 69.5 % ) ( OR = 1.46 ) , disc space narrowing in 33 ( 24.8 % ) and in 59 ( 26.5 % ) ( OR = 0.98 ) , and foraminal stenosis in 6 ( 4.5 % ) , and in 20 ( 9.0 % ) ( OR = 0.52 ) , respectively . Neck pain was observed in 34 WAD patients ( 25.6 % ) and 22 control subjects ( 9.9 % ) ( P < 0.0001 ) . There was no statistically significant correlation between neck pain and progression in each MR finding in either group . Conclusion . The results of this study suggest that , although some WAD patients are more likely to suffer from long-lasting neck pain , MRI findings can not explain the symptoms Study Design . Population ‐based , cross‐sectional mailed survey . Objective . To determine the lifetime , period , and point prevalence of neck pain and its related disability among Saskatchewan adults and investigate the presence and strength of nonresponse bias . Summary of Background Data . In Europe , the life‐time and point prevalence of neck pain is almost as high as the prevalence of low back pain . Similarly , chronic neck pain is highly prevalent and a common source of disability in the working‐age population . However , no studies specifically have documented the prevalence of neck pain and its related disability in North America . Methods . The Saskatchewan Health and Back Pain Survey was mailed to 2184 r and omly selected Saskatchewan adults aged 20‐69 years . Fifty‐five percent of the study population participated . The presence of nonresponse bias was investigated through logistic regression and wave analysis . The Chronic Pain Question naire was used to classify the severity of chronic neck pain . Results . The age‐st and ardized lifetime prevalence of neck pain is 66.7 % ( 95 % confidence interval , 63.8‐69.5 ) , and the point prevalence is 22.2 % ( 95 % confidence interval , 19.7‐24.7 ) . The age‐st and ardized 6‐month prevalence of low‐intensity and low‐disability neck pain is 39.7 % ( 95 % confidence interval , 36.7‐42.7 ) , whereas it is 10.1 % ( 95 % confidence interval , 8.2‐11.9 ) for high‐intensity and low‐disability neck pain and 4.6 % ( 95 % confidence interval , 3.3‐5.8 ) for significantly disabling neck pain . The prevalence of low‐intensity and low‐disability neck pain decreases with age . More women experience high‐disability neck pain than men . Wave analysis suggests that the point prevalence and 6‐month prevalence of high‐intensity and low‐disability neck pain are overestimated in this survey . Conclusion . This cross‐sectional study shows that neck pain is highly prevalent in Saskatchewan and that it significantly disables 4.6 % ( 95 % confidence interval , 3.3‐5.8 ) of the adult population The authors undertook a case-control study of chronic neck pain and whiplash injuries in nine states in the United States to determine whether whiplash injuries contributed significantly to the population of individuals with chronic neck and other spine pain . Four hundred nineteen patients and 246 controls were r and omly enrolled . Patients were defined as individuals with chronic neck pain , and controls as those with chronic back pain . The two groups were surveyed for cause of chronic pain as well as demographic information . The two groups were compared using an exposure-odds ratio . Forty-five per cent of the patients attributed their pain to a motor vehicle accident . An OR of 4.0 and 2.1 was calculated for men and women , respectively . Based on the results of the present study , it reasonable to infer that a significant proportion of individuals with chronic neck pain in the general population were originally injured in a motor vehicle accident & NA ; Although neck pain is a common source of disability , little is known about its incidence and course . We conducted a population ‐based cohort study of 1100 r and omly selected Saskatchewan adults to determine the annual incidence of neck pain and describe its course . Subjects were initially surveyed by mail in September 1995 and followed‐up 6 and 12 months later . The age and gender st and ardized annual incidence of neck pain is 14.6 % ( 95 % confidence interval : 11.3 , 17.9 ) . Each year , 0.6 % ( 95 % confidence interval : 0.0–1.1 ) of the population develops disabling neck pain . The annual rate of resolution of neck pain is 36.6 % ( 95 % confidence interval : 32.7 , 40.5 ) and another 32.7 % ( 95 % confidence interval : 25.5 , 39.9 ) report improvement . Among subjects with prevalent neck pain at baseline , 37.3 % ( 95 % confidence interval : 33.4 , 41.2 ) report persistent problems and 9.9 % ( 95 % confidence interval : 7.4 , 12.5 ) experience an aggravation during follow‐up . Finally , 22.8 % ( 95 % confidence interval : 16.4 , 29.3 ) of those with prevalent neck pain at baseline report a recurrent episode . Women are more likely than men to develop neck pain ( incidence rate ratio=1.67 , 95 % confidence interval 1.08–2.60 ) ; more likely to suffer from persistent neck problems ( incidence rate ratio=1.19 , 95 % confidence interval 1.03–1.38 ) and less likely to experience resolution ( incidence rate ratio=0.75 , 95 % confidence interval 0.63–0.88 ) . Neck pain is a disabling condition with a course marked by periods of remission and exacerbation . Contrary to prior belief , most individuals with neck pain do not experience complete resolution of their symptoms and disability Objective : To prospect ively examine the course of pain and other neurologic complaints in patients with acute whiplash injury and in controls with acute ankle injury . Methods : Patients with acute whiplash ( n = 141 ) and ankle-injured controls ( n = 40 ) were consecutively sample d , and underwent interview and examination after 1 week and 1 , 3 , 6 , and 12 months . Outcome measures were pain intensity , pain frequency , and associated symptoms . Results : Initial overall pain intensity above lower extremities ( pain in neck , head , shoulder-arm , and low back ) was similar in patients with whiplash ( median Visual Analogue Scale [VAS]0–100 of 20 [ 25th and 75th percentile , 4 , 39 ] ) and ankle-injured controls ( median VAS0–100 of 15 [ 5 , 34 ] ) . Whiplash-injured patients reported median overall VAS0–100 pain intensity above lower extremities of 23 ( 12 , 40 ) after 11 days and 14 ( 12 , 40 ) after 1 year . Controls reported pain intensity of 0 ( 0 , 4 ) after 12 days and 0 ( 0 , 9 ) after 1 year . Reported overall pain frequency above lower extremities was 96 % after 11 days and 74 % after 1 year in whiplash-injured patients and 33 % after 12 days and 47 % after 1 year in controls . Associated neurologic symptoms were two to three times more common after whiplash injury . Correlation was found between pain intensity and associated symptoms in whiplash-injured patients but not controls . Conclusion : Pain occurs with high frequency but low intensity after whiplash and ankle injury . Associated neurologic symptoms were not correlated to pain in ankle-injured controls , but were correlated to pain in patients with whiplash injury . Persistent symptoms in whiplash-injured patients may be caused by both specific neck injury – related factors and nonspecific post-traumatic reactions . Disability was only encountered in the whiplash group The objective of this population -based cohort study was to investigate the association between a lifetime history of neck injury from a motor vehicle collision and the development of troublesome neck pain . The current evidence suggests that individuals with a history of neck injury in a traffic collision are more likely to experience future neck pain . However , these results may suffer from residual confounding . Therefore , there is a need to test this association in a large population -based cohort with adequate control of known confounders . We formed a cohort of 919 r and omly sample d Saskatchewan adults with no or mild neck pain in September 1995 . At baseline , participants were asked if they ever injured their neck in a motor vehicle collision . Six and twelve months later , we asked about the presence of troublesome neck pain  ( grade II – IV ) on the chronic pain grade question naire . Multivariable Cox regression was used to estimate the association between a lifetime history of neck injury in a motor vehicle collision and the onset of troublesome neck pain while controlling for known confounders . The follow-up rate was 73.5 % ( 676/919 ) at 6 months and 63.1 % ( 580/919 ) at 1 year . We found a positive association between a history of neck injury in a motor vehicle collision and the onset of troublesome neck pain after controlling for bodily pain and body mass index ( adjusted HRR = 2.14 ; 95 % CI 1.12–4.10 ) . Our analysis suggests that a history of neck injury in a motor vehicle collision is a risk factor for developing future troublesome neck pain . The consequences of a neck injury in a motor vehicle collision can have long lasting effects and predispose individuals to experience recurrent episodes of neck pain OBJECTIVES In Lithuania , there is little awareness of the notion that chronic symptoms may result from rear end collisions via the so-called whiplash injury . After most such collisions no contact with the health service is established . An opportunity therefore exists to study post-traumatic pain without the confounding factors present in western societies . METHODS In a prospect i ve , controlled inception cohort study , 210 victims of a rear end collision were consecutively identified from the daily records of the Kaunas traffic police .  Neck pain and headache were evaluated by mailed question naires shortly after the accident , after 2 months , and after 1 year . As controls , 210 sex and age matched subjects were r and omly taken from the population register of the same geographical area and evaluated for the same symptoms immediately after their identification and after 1 year . RESULTS Initial pain was reported by 47 % of accident victims ; 10 % had neck pain alone , 18 % had neck pain together with headache , and 19 % had headache alone . The median duration of the initial neck pain was 3 days and maximal duration 17 days . The median duration of headache was 4.5 hours and the maximum duration was 20 days . After 1 year , there were no significant differences between the accident victims and the control group concerning frequency and intensity of these symptoms . CONCLUSIONS In a country were there is no preconceived notion of chronic pain arising from rear end collisions , and thus no fear of long term disability , and usually no involvement of the therapeutic community , insurance companies , or litigation , symptoms after an acute whiplash injury are self limiting , brief , and do not seem to evolve to the so-called late whiplash syndrome 
    Output:
    
agent
CONCLUSIONS There was a consistent positive association among studies that have examined the association between MVC-related neck injury and future NP .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Study Design . A prospect i ve 10-year follow-up study of patients with whiplash-associated disorders ( WAD ) and asymptomatic volunteers . Objective . To clarify long-term impact of whiplash injury on patient 's symptoms and on magnetic resonance imaging ( MRI ) findings of the cervical spine . Summary of Background Data . Long-term prognosis of WAD has not been fully eluci date d. Methods . Between 1993 and 1996 , we conducted cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers , all of whom underwent MRI of the cervical spine .  For this follow-up study , 133 WAD patients and 223 control subjects were recruited again . All participants underwent follow-up MRI and physical examination , and answered to question naires regarding neck symptoms . Evaluation of MRI included decrease in signal intensity of discs , posterior disc protrusion , disc space narrowing , and foraminal stenosis using 2 to 4 numerical grade s. Increase in the numerical grade s by one or more was considered to be progression of degenerative changes . Results . Progression of decrease in signal intensity was observed in 109 WAD patients ( 82.0 % ) , and 132 control subjects ( 59.2 % ) , ( age , sex adjusted odds ratio [ OR ] : 3.06 ) , posterior disc protrusion in 101 ( 75.9 % ) and in 155 ( 69.5 % ) ( OR = 1.46 ) , disc space narrowing in 33 ( 24.8 % ) and in 59 ( 26.5 % ) ( OR = 0.98 ) , and foraminal stenosis in 6 ( 4.5 % ) , and in 20 ( 9.0 % ) ( OR = 0.52 ) , respectively . Neck pain was observed in 34 WAD patients ( 25.6 % ) and 22 control subjects ( 9.9 % ) ( P < 0.0001 ) . There was no statistically significant correlation between neck pain and progression in each MR finding in either group . Conclusion . The results of this study suggest that , although some WAD patients are more likely to suffer from long-lasting neck pain , MRI findings can not explain the symptoms Study Design . Population ‐based , cross‐sectional mailed survey . Objective . To determine the lifetime , period , and point prevalence of neck pain and its related disability among Saskatchewan adults and investigate the presence and strength of nonresponse bias . Summary of Background Data . In Europe , the life‐time and point prevalence of neck pain is almost as high as the prevalence of low back pain . Similarly , chronic neck pain is highly prevalent and a common source of disability in the working‐age population . However , no studies specifically have documented the prevalence of neck pain and its related disability in North America . Methods . The Saskatchewan Health and Back Pain Survey was mailed to 2184 r and omly selected Saskatchewan adults aged 20‐69 years . Fifty‐five percent of the study population participated . The presence of nonresponse bias was investigated through logistic regression and wave analysis . The Chronic Pain Question naire was used to classify the severity of chronic neck pain . Results . The age‐st and ardized lifetime prevalence of neck pain is 66.7 % ( 95 % confidence interval , 63.8‐69.5 ) , and the point prevalence is 22.2 % ( 95 % confidence interval , 19.7‐24.7 ) . The age‐st and ardized 6‐month prevalence of low‐intensity and low‐disability neck pain is 39.7 % ( 95 % confidence interval , 36.7‐42.7 ) , whereas it is 10.1 % ( 95 % confidence interval , 8.2‐11.9 ) for high‐intensity and low‐disability neck pain and 4.6 % ( 95 % confidence interval , 3.3‐5.8 ) for significantly disabling neck pain . The prevalence of low‐intensity and low‐disability neck pain decreases with age . More women experience high‐disability neck pain than men . Wave analysis suggests that the point prevalence and 6‐month prevalence of high‐intensity and low‐disability neck pain are overestimated in this survey . Conclusion . This cross‐sectional study shows that neck pain is highly prevalent in Saskatchewan and that it significantly disables 4.6 % ( 95 % confidence interval , 3.3‐5.8 ) of the adult population The authors undertook a case-control study of chronic neck pain and whiplash injuries in nine states in the United States to determine whether whiplash injuries contributed significantly to the population of individuals with chronic neck and other spine pain . Four hundred nineteen patients and 246 controls were r and omly enrolled . Patients were defined as individuals with chronic neck pain , and controls as those with chronic back pain . The two groups were surveyed for cause of chronic pain as well as demographic information . The two groups were compared using an exposure-odds ratio . Forty-five per cent of the patients attributed their pain to a motor vehicle accident . An OR of 4.0 and 2.1 was calculated for men and women , respectively . Based on the results of the present study , it reasonable to infer that a significant proportion of individuals with chronic neck pain in the general population were originally injured in a motor vehicle accident & NA ; Although neck pain is a common source of disability , little is known about its incidence and course . We conducted a population ‐based cohort study of 1100 r and omly selected Saskatchewan adults to determine the annual incidence of neck pain and describe its course . Subjects were initially surveyed by mail in September 1995 and followed‐up 6 and 12 months later . The age and gender st and ardized annual incidence of neck pain is 14.6 % ( 95 % confidence interval : 11.3 , 17.9 ) . Each year , 0.6 % ( 95 % confidence interval : 0.0–1.1 ) of the population develops disabling neck pain . The annual rate of resolution of neck pain is 36.6 % ( 95 % confidence interval : 32.7 , 40.5 ) and another 32.7 % ( 95 % confidence interval : 25.5 , 39.9 ) report improvement . Among subjects with prevalent neck pain at baseline , 37.3 % ( 95 % confidence interval : 33.4 , 41.2 ) report persistent problems and 9.9 % ( 95 % confidence interval : 7.4 , 12.5 ) experience an aggravation during follow‐up . Finally , 22.8 % ( 95 % confidence interval : 16.4 , 29.3 ) of those with prevalent neck pain at baseline report a recurrent episode . Women are more likely than men to develop neck pain ( incidence rate ratio=1.67 , 95 % confidence interval 1.08–2.60 ) ; more likely to suffer from persistent neck problems ( incidence rate ratio=1.19 , 95 % confidence interval 1.03–1.38 ) and less likely to experience resolution ( incidence rate ratio=0.75 , 95 % confidence interval 0.63–0.88 ) . Neck pain is a disabling condition with a course marked by periods of remission and exacerbation . Contrary to prior belief , most individuals with neck pain do not experience complete resolution of their symptoms and disability Objective : To prospect ively examine the course of pain and other neurologic complaints in patients with acute whiplash injury and in controls with acute ankle injury . Methods : Patients with acute whiplash ( n = 141 ) and ankle-injured controls ( n = 40 ) were consecutively sample d , and underwent interview and examination after 1 week and 1 , 3 , 6 , and 12 months . Outcome measures were pain intensity , pain frequency , and associated symptoms . Results : Initial overall pain intensity above lower extremities ( pain in neck , head , shoulder-arm , and low back ) was similar in patients with whiplash ( median Visual Analogue Scale [VAS]0–100 of 20 [ 25th and 75th percentile , 4 , 39 ] ) and ankle-injured controls ( median VAS0–100 of 15 [ 5 , 34 ] ) . Whiplash-injured patients reported median overall VAS0–100 pain intensity above lower extremities of 23 ( 12 , 40 ) after 11 days and 14 ( 12 , 40 ) after 1 year . Controls reported pain intensity of 0 ( 0 , 4 ) after 12 days and 0 ( 0 , 9 ) after 1 year . Reported overall pain frequency above lower extremities was 96 % after 11 days and 74 % after 1 year in whiplash-injured patients and 33 % after 12 days and 47 % after 1 year in controls . Associated neurologic symptoms were two to three times more common after whiplash injury . Correlation was found between pain intensity and associated symptoms in whiplash-injured patients but not controls . Conclusion : Pain occurs with high frequency but low intensity after whiplash and ankle injury . Associated neurologic symptoms were not correlated to pain in ankle-injured controls , but were correlated to pain in patients with whiplash injury . Persistent symptoms in whiplash-injured patients may be caused by both specific neck injury – related factors and nonspecific post-traumatic reactions . Disability was only encountered in the whiplash group The objective of this population -based cohort study was to investigate the association between a lifetime history of neck injury from a motor vehicle collision and the development of troublesome neck pain . The current evidence suggests that individuals with a history of neck injury in a traffic collision are more likely to experience future neck pain . However , these results may suffer from residual confounding . Therefore , there is a need to test this association in a large population -based cohort with adequate control of known confounders . We formed a cohort of 919 r and omly sample d Saskatchewan adults with no or mild neck pain in September 1995 . At baseline , participants were asked if they ever injured their neck in a motor vehicle collision . Six and twelve months later , we asked about the presence of troublesome neck pain  ( grade II – IV ) on the chronic pain grade question naire . Multivariable Cox regression was used to estimate the association between a lifetime history of neck injury in a motor vehicle collision and the onset of troublesome neck pain while controlling for known confounders . The follow-up rate was 73.5 % ( 676/919 ) at 6 months and 63.1 % ( 580/919 ) at 1 year . We found a positive association between a history of neck injury in a motor vehicle collision and the onset of troublesome neck pain after controlling for bodily pain and body mass index ( adjusted HRR = 2.14 ; 95 % CI 1.12–4.10 ) . Our analysis suggests that a history of neck injury in a motor vehicle collision is a risk factor for developing future troublesome neck pain . The consequences of a neck injury in a motor vehicle collision can have long lasting effects and predispose individuals to experience recurrent episodes of neck pain OBJECTIVES In Lithuania , there is little awareness of the notion that chronic symptoms may result from rear end collisions via the so-called whiplash injury . After most such collisions no contact with the health service is established . An opportunity therefore exists to study post-traumatic pain without the confounding factors present in western societies . METHODS In a prospect i ve , controlled inception cohort study , 210 victims of a rear end collision were consecutively identified from the daily records of the Kaunas traffic police .  Neck pain and headache were evaluated by mailed question naires shortly after the accident , after 2 months , and after 1 year . As controls , 210 sex and age matched subjects were r and omly taken from the population register of the same geographical area and evaluated for the same symptoms immediately after their identification and after 1 year . RESULTS Initial pain was reported by 47 % of accident victims ; 10 % had neck pain alone , 18 % had neck pain together with headache , and 19 % had headache alone . The median duration of the initial neck pain was 3 days and maximal duration 17 days . The median duration of headache was 4.5 hours and the maximum duration was 20 days . After 1 year , there were no significant differences between the accident victims and the control group concerning frequency and intensity of these symptoms . CONCLUSIONS In a country were there is no preconceived notion of chronic pain arising from rear end collisions , and thus no fear of long term disability , and usually no involvement of the therapeutic community , insurance companies , or litigation , symptoms after an acute whiplash injury are self limiting , brief , and do not seem to evolve to the so-called late whiplash syndrome 
    Output:
    