Low back pain: what is the long-term course? A review of studies of general patient populations

17 Pages·2003·0.3 MB·English

Eur Spine J (2003) 12:149–165
DOI 10.1007/s00586-002-0508-5 LITERATURE REVIEW
Low back pain:
Lise Hestbaek
Charlotte Leboeuf-Yde what is the long-term course?
Claus Manniche
A review of studies
of general patient populations
Abstract It is often claimed that up covery. Thirty-six articles were in-
Received: 1 June 2002
to 90% of low back pain (LBP) cluded. The results of the review
Revised: 29 September 2002
Accepted: 18 October 2002 episodes resolve spontaneously showed that the reported proportion
Published online: 28 January 2003 within 1 month. However, the litera- of patients who still experienced pain
©Springer-Verlag 2003 ture in this area is confusing due to after 12 months was 62% on average
considerable variations regarding the (range 42–75%), the percentage of
exact definitions of LBP as well as patients sick-listed 6 months after in-
recovery. Therefore, the claim – at- clusion into the study was 16%
tractive as it might be to some – may (range 3–40%), the percentage who
not reflect reality. In order to investi- experienced relapses of pain was
gate the long-term course of incident 60% (range 44–78%), and the per-
and prevalent cases of LBP, a sys- centage who had relapses of work
tematic and critical literature review absence was 33% (range 26–37%).
was undertaken. A comprehensive The mean reported prevalence of
search of the topic was carried out LBP in cases with previous episodes
utilizing both Medline and EMBASE was 56% (range 14–93%), which
databases. The Cochrane Library and compared with 22% (range 7–39%)
the Danish Article Base were also for those without a prior history of
screened. Journal articles following LBP. The risk of LBP was consis-
the course of LBP without any known tently about twice as high for those
intervention were included, regard- with a history of LBP. The results of
less of study type. However, the pop- the review show that, despite the
ulation had to be representative of methodological variations and the
the general patient population and a lack of comparable definitions, the
L. Hestbaek (✉ ) · C. Manniche follow-up of at least 12 months was overall picture is that LBP does not
The Backcenter, Ringe Hospital, a requirement. Data were extracted resolve itself when ignored. Future re-
Odense University Hospital, independently by two reviewers us- search should include subgroup analy-
5950 Ringe, Denmark ing a standard check list.The in- ses and strive for a consensus regard-
e-mail: [email protected],
cluded articles were also indepen- ing the precise definitions of LBP.
Tel.: [phone]
dently assessed for quality by the
C. Leboeuf-Yde same two reviewers before they were Keywords Low back pain · Natural
The Medical Research Unit
studied in relation to the course of course · Prognosis · Review ·
in Ringkjøbing County,
Ringkøbing, Denmark LBP using various definitions of re- Recovery
cal course is defined as the development subsequent to di-
Introduction
agnosis and the initiation of treatment. Obviously, without
a thorough understanding of the natural history of a dis-
The natural history of a disease relates to its development ease, the background for evaluating the clinical course is
in the absence of clinical intervention, whereas the clini- lacking, and therapeutic interventions cannot be assessed
150
in a rational manner. In fact, inadequate understanding of Materials and methods
the course of a disease can lead to false conclusions about
the need for, as well as the benefit of, therapeutic inter- Search strategy
ventions.
The literature search was modified from the comprehensive search
Presently, the literature in the area is confusing and in-
strategy recommended by the Back Review Group of the Cochrane
conclusive. The most obvious reason for this confusion is Collaboration [38].
the lack of distinction between outcome parameters. For
1. The MEDLINE database was searched from the beginning of
example, one study, which seems to be partly responsible the database (1992 via PubMed) to June 1999. The decision to
for the widely accepted belief that 90% of low back pain use the more easily accessible database from 1992 was made
(LBP) patients recover within 1 month, in fact showed because the study quality was presumed to be better in the
1990s and the up-to-date literature more relevant. The search
that 90% LBP patients stopped consulting their medical
combined the terms “low back pain” (MeSH)/ “back pain” (free
practitioner within 1 month [15]. Furthermore, Waddell text)/ “low back” (free text) with one or more of the following
has been cited for postulating, that 80–90% of LBP at- free text words: “epidemiology”, “natural history”, “natural
tacks resolve within 6 weeks [9], but in fact he refers to course”, “prospective”, “longitudinal”, “follow-up” or “prog-
nos*” or the MeSH terms: “prognosis” or “survival analysis”.
return to work – not cessation of pain [43]. Another study
An additional Medline search specifically for randomised con-
that has had an impact on the spontaneous recovery belief, trolled trials did not reveal additional relevant studies.
also studied return to work and found that approximately 2. A similar search, modified as necessary, was run in EMBASE
75% of sick-listed LBP patients returned to work within (the terms “prognosis” and “survival analysis” were not included
here).
1 month [2]. However, return to work provides an incom-
3. The Cochrane Library was screened for reviews on the topic.
plete picture of the natural course of LBP, because chronic
4. Relevant systematic reviews and their references were screened.
pain patients may “move” in and out of employment, re- 5. Den Danske Artikelbase (the Danish Article Base) was searched
turn to work at physically less demanding jobs, or reduce for “low back pain”/ “back pain”.
their workload [18]. In contrast, Croft et al. demonstrated Article selection was based on 1948 titles, and abstracts were
that 75% of LBP patients from general practice still expe- screened for suitability by the first author. In addition to epidemi-
rienced pain 1 year later [9]. Obviously, return to work or ologic studies, randomized controlled trials were included if they
contained a control group that received only sham treatment or
cessation of medical consultations does not necessarily
treatment from a general practitioner. In studies where there was a
correlate with the cessation of symptoms. Although the statistically significant difference in treatment results for the inter-
various outcome measures (pain, disability, sick leave and vention as compared to the control group, only data from the con-
medical consultations) are related, they should not be con- trol group were considered. Otherwise all relevant data were in-
cluded. Eighty-four articles were found and screened for inclusion
sidered interchangeable [14].
and exclusion criteria.
Additionally, the choice of cohort represents a problem
when studying the natural course of a disease. In classical
epidemiologic study designs (such as cross-sectional or Criteria for consideration
longitudinal surveys) the cohort is made up of prevalent
cases, including subjects at different stages of the disease, The inclusion criteria were:
which results in an “apples-and-pears cohort”. • Original journal articles from the Western world
The present confusion may also be partly explained by • Articles written in English, Danish, Norwegian or Swedish
a lack of distinction between the short-term and long-term • Original studies
• A sample size of 50 or more (in the case of randomised con-
prognosis. LBP is characterized by variation and change,
trolled trails this applies to the control group) was arbitrarily
rather than absolute recovery [40]. Thus, concentration on chosen
the short-term development might present the condition as • Follow-up period of at least 12 months
cured, whereas long-term follow-up may reveal a more re- The exclusion criteria were:
current scenario. Therefore, this review will concentrate
• Articles relating to chronic LBP (absence from work for a mini-
on the long-term course of LBP.
mum of 6 months), because this is usually considered one of the
Although this area has been extensively studied, it re- possible end-points of back pain and because a population of
mains difficult to gain a clear overview. Therefore, we this type is not representative of the general population
• Studies based on a specific population such as a specific occu-
conducted a systematic critical review of the epidemio-
pational group or pregnant women
logic literature to improve our understanding of the nat- • Studies of LBP due to acute injury
ural course of LBP and, in particular, to investigate
This selection procedure identified 36 articles, which were in-
whether there is evidence to support the popular claim of
cluded in this review.
80–90% spontaneous recovery within 1 month.
Data extraction
All included articles were reviewed for relevant information using
a standard check list (Appendix 1). This was done independently
by two reviewers (L.H. and C.L-Y.) and disagreements were re-
151
solved by consensus. Data on study populations, study design and views or questionnaires. All other criteria were ful-
outcome measures (pain, sick leave, disability, recurrences and filled, and no studies scored below 67%. It was there-
consultations) were noted and, finally, information was retrieved
fore decided not to exclude any of the studies on the
in relation to nationality, age and gender.
basis of the quality assessment.
Quality assessment
Number and type of studies
All the studies were independently assessed for methodological
quality as it relates to natural history by two reviewers (L.H. and
C.L-Y.) using a standard check list. Where disagreement occurred, The 36 included studies were published between 1981 and
the matter was discussed and consensus reached. No existing stan- 1999 (October). Only four studies were published in the
dard criteria list was found suitable, since following the course of
1980s [1, 2, 27, 37]. Seven studies were randomised con-
an event does not require the same method as a randomised con-
trolled trial. In contrast to cause-effect research, in which internal trolled trials [6, 16, 17, 25, 34, 35, 39], five were retro-
validity is of utmost importance, representativeness and general- spective observational studies [2, 19, 20, 21, 46], and the
ization are more important in descriptive epidemiological studies remaining 24 were prospective observational studies. No
[3]. A list of specific criteria was adapted from Von Korff [40] to
difference in outcome was noted between these three
suit the requirements of the subject, including both descriptive (ex-
ternal validity) and methodological (internal validity) criteria. types of design.
Thus, the general quality of the studies was not assessed, but only
quality as it relates to natural history, and the assigned quality score
does not necessarily reflect the quality of the study as a whole. The
Study populations
criteria for obtaining a maximum score are listed in Appendix 1.
Based on these, a quality score was assigned to each study and the
results are presented in Table 1. The full quality assessment can be The majority of studies had a population size between 100
obtained from the authors. and 500, with a range of 62 [21] to 89,190 [20]. The exact
numbers can be seen in Table 1.
Analysis Study populations were drawn from several sources:
the army [10], schools [5, 21, 29, 32], the general popula-
It is possible that the results differ in relation to the definition of tion [28, 30] workers receiving compensation [1, 2, 20, 25,
recovery, in such a way that the consequences of LBP (e.g. med-
27, 35, 37] and clinical populations [4, 6, 7, 8, 9, 12, 13,
ical consultations and absence from work) would result in a seem-
16, 17, 19, 22, 23, 24, 31, 33, 34, 36, 39, 42, 44, 45, 46].
ingly quicker recovery than actual symptoms. Therefore, the vari-
ous outcomes, such as sick leave, recurrence of sick leave, consul- There were two inception cohorts [28, 44] (first onset
tations, disability, pain and recurrence of pain, were studied sepa- of disease) and the rest were either consecutive (included
rately. Furthermore, as sick leave and consultations may depend on
as they appear at the study site) or prevalent (all cases with
legislation, which varies between countries, national differences in
LBP at a certain point in time) cases. With only two in-
relation to sick leave were also analysed. We also attempted to in-
vestigate the course of LBP as it relates to age, gender, and a pre- ception studies, it is not possible to determine whether the
vious history of LBP. results from such cohorts differ from those of other types.
Results
Description of LBP
Twenty-eight observational studies and eight randomised
The gluteal folds were commonly defined as the lower
controlled trials fulfilled our inclusion criteria. Informa-
border in the definition of LBP [16, 17, 22, 23, 24, 28, 31,
tion regarding these 36 studies is presented in Table 1.
36, 45], whereas the upper border varied from the scapula
Studies are listed in alphabetical order according to the
[45] to the first lumbar vertebra [28]. In several studies
name of the first author.
the only description provided was “back pain” or “low
back pain”. Patients with radiating pain were specifically
excluded in only one study [17]. In 14 studies [2, 4, 6, 16,
Quality of data
20, 21, 22, 23, 27, 34, 35, 37, 39, 46], both patients with
and those without leg pain were included, and in the re-
The overall quality was generally good, but the following
maining 21 studies there was no mention of radiating pain
concerns are noteworthy:
at all.
1. In 42% (13/31) of the relevant articles, comparison of The duration of symptoms at baseline was mentioned
responders and non-responders was missing. in only one-third of the studies [6, 7, 8, 16, 17, 19, 25, 31,
2. The exact anatomical demarcation of LBP was not de- 33, 34, 39, 44, 45]. Because of this lack of homogeneity in
fined in 33% (12/36) of the studies. relation to LBP definitions, time of inception and follow-
3. In 8% (3/36) of the studies, data had not been collected up periods, it is difficult to compare results and to reach
in the preferred manner, i.e. sick leave data from ad- definitive conclusions. This heterogeneity is illustrated in
ministrative sources and symptom data from inter- Table 2 and Table 3.
152
practitioner, Reviewers’comments Transition inpain statusnot reported The controlgroup mighthave beeninfluencedby the“controlbooklet”,which seemsto reinforcefear avoid-ance
al
ds ratio, GP gener Results 37.1% had recur-rences of absencefrom work. Aver-age no. of epi-sodes: 2.65 over3 yrsStill absent at:12 days: 50%1 month: ~25%6 months: ~5% “better”/”not”(n)1 mth: 9/903 mths: 20/671 yr:29/59“improving”/”not” 1 mth: 45/533 mths: 55/321 yr: 53/36Recurrent LBP of96 pts with LBP atindex: yr 1: 44%yr 5: 59%Point prevalence:age 11: 3.2%age 12: 3.9%age 13: 6.4%age 14: 10.0%age 15: 12.9%Reduction in painafter 1 yr, mean(SD):“pain at worst”:68.7(18.5)50.8Æ(27.8)“pain at best”:15.6(18.7)10.6Æ(17.8)Reduction inRoland Disability:~10.4~4.4Æ56% free of backpain after 3 mths
d
d trial, OR o Outcomemeasures Sick leave Sick leave Pain(“completelybetter” or“steadilyimproving”) Pain Pain, dis-ability Pain
e
ndomised controllulo-skeletal) Description ofLBP Musculo-skele-tal complaints inthe lumbar orlumbosacralregion Pain, ache,stiffness orfatigue in thelower backw/wo legpain Back and/orlower limb pain LBP, other thanoccasionaltwinge Acute orrecurrent LBPw/wo leg pain Back pain lessthan 10 weeks
ac
studies (LBP low back pain, RCT rassification of Primary Care, MS mus Time & type ofSample sizefollow-up& responserate 1641;1, 2 and 3 years asresponse raterecorded in Quebecnot applicableWorkers’ Compen-sation Board 940; responseAll LBP absencesrate notrecorded at theapplicablePublic HealthInsurance Officefrom 1955 to 1976 1 mth, 3 mths and109/87 (82%)1 yr by question-(with full datanaire or office visitset) Yrs 1 and 2 by216 at index,interview, yrs 3, 4147 at year 5and 5 by question-due to normalnairemovementfrom the areaand absencefrom schoolon the day ofquestioning Index:2 wks, 3 mths and162/1881 yr by postal(86%);questionnairefollow-up:126/162(78%) 1645; follow-6 and 22 mths byup: 754/ 921telephone inter-(free of painviewafter 3 mths)(82%)
e 36 included nternational Cl Age &gender Working age(50% btn 25and 44 yrs);84.3% male 40–47 yrs;all male Mean age41.8 yrs;54% male Mean age11.7 yrs atindex;~50% male Mean age(SD) 44.7(12.2) yrs;45% male Mean age41.7 yrs;49% male
hI
xtracted from tnization, ICPC Description ofsample Representativesample of allworkers com-pensated forback pain in1981Randomly se-lected fromthe census re-gister in a bigcity in Sweden SequentialLBP patientsattending anorthopaedicout-patientpractice anda GP Entire intakeclass of 1985in a mixed-sexschool Patients con-sulting 6 GPor osteopathicclinics forLBP of lessthan 3 months’duration Sequentialpatients in 208primary carepractices
Table 1 Details of the data eHMO Health Maintenance Orga Design andAuthor, (year)cohortcountry andquality score Prospective,Abenhaim etconsecutiveal. (1988) [1],Canada, 100%cases Anderson et al.Retrospec-(1983) [2],tive, consec-Sweden, 100%utive cases Prospective,Burton et al.consecutive(1991) [4],casesUK, 83% Burton et al.Prospective,(1996) [5], UKprevalent83%cases Burton et al.Prospective,(1999) [6],consecutiveUK, 100%cases, RCT Carey et al.Prospective,(1999) [7],consecutiveUSA, 67%cases
153
Selectionbias mayhave re-sulted inslight under-estimationof recovery.This is ac-counted forin the text.
54% had recur-rences from 6 to22 mths1.49% seekingdisability after22 mths Roland-Morris at 22 mths(0–23): 2.9–3.9“Bothersomenes”(0–10):1 wk: ~44 wks: ~3.212 weks: ~3.21 yr: ~2.72 yrs: ~2.4Roland Disability(0–24):Index: ~11.61 wk: ~7.64 wks: ~5.012 wks: ~4.51 yr:~4.82 yrs: ~4.6Recovery:1 wk: 2%3 mths: 21%12 mths: 25%Recovery withinitial pain anddisability: 18%Recovery withinitial pain ordisability: 44%Consultations:3 mths: 40%12 mths: 8%% at follow-upwith the samestatus as at index:Never LBP:72/356 (20%)LBP once: 17/66(26%)LBP occasionally:92/284 (32%)LBP constantly:6/11 (55%)Lifetime prev: 73%Annual inc.: 53%Point prev.: 26%
Recurrence Disability Pain(“bother-someness”),disability Pain anddisability Consulta-tions Pain
n r
n ai we s
Low back pai>7 days Generalised pthat includedpain in the loback Any back-re-lated problem
1, 4 and 12 wksand 1 and 2 yrsby telephoneinterview 1 wk, 3 and12 mths byinterview andreview of medicalrecords over theyear Index and 12 yrslater by question-naire
Index:493/714,(69%);follow-up:55/66 (83%) Medicalrecords: 463;Interviews:170/218(77%) 784/1058(37 with LBPat index)(74%)
20–64 yrs;52% male 18–75 yrs;41% male ~18 yrs atindex; allmale
Patients con-sulting forLBP in twoGP clinicswho still hadpain 7 dayslater Patients con-sulting two GPpractices for anew episodeof LBP (noLBP the previ-ous 3 months) Militaryrecruits
e,e e,e e,
vv vv v
ospectinsecutises ospectinsecutises ospectievalentses
Prcoca Prcoca Prprca
Cherkin et al.(1998) [8],USA 67% Croft et al.(1998) [9], UK(study sampledrawn fromthe samepopulation as[31] and [36]),100% Darre et al.(1999) [10],Denmark, 83%
154
Reviewers’comments All absencesincluded,unknownhow manyof these areback-related Variousfollow-uptimes In Norwaythere is100% sick-ness benefitfrom 1st dayto 12 mths
Results Mean RolandMorris:At index: 34.40After 1 yr: 25.20After 2 yrs: 22.44 Roland-Morris>50:At index: ~32%After 2 yrs: ~20% 78% had at least1 recurrence.Mean no. ofrecurrences: 1.6 Control group:Absence at least1 day:In mth 1: 61%In mths 2&3: 27%In mths 4–12:31% Months off work:median (range)Compensation:Male: 12(0.25–84)Female: 15(0–132)No compensation:Male: 0.25(0–180)Female: 0.5(0–22)Still absent at:1 mth: ~65%3 mths: ~30%6 mths ~15%In 1 year:1 absence: 74%2 absences: 19%>2 absences: 7%
Outcomemeasures Disability Disability Pain recur-rence Sick leave Sick leave Sick leave
Description ofLBP Back pain Back pain T12 to glutealfolds, <3 mths T12 to glutealfolds, <3 wks,no radiation Back, hip and/orleg pain, <1 wk ICPC codesL02, L03, L84,L86 (LBP w/woradiation)
Time & type offollow-up 1 month, 1 and 2yrs by interview 4–6 wks and 2 yrsby telephone inter-view 2 wks, 4 wks and12 mths by GP,monthly question-naire in between 2 wks, 4 wks and12 mths by GP,monthly question-naire in between Interview byauthor at differenttimes. Medianfollow-up: 47–56months (4 groups) All LBP absencesregistered in theNational InsuranceAdministration1995 and 1966
ee
Sample size& responserate Index:1213/1685(72%);follow-up:1009/1213(83%)Index:1213/1685(72%);follow-up:1024/1213(84%)Index:473/525(90%);follow-up:413/473(87%)divided into3 groups322/363(89%),Control:108/119(90%) 287/300(96%) 89,190Response ratnot applicabl
Age &gender Mean age(SD) 46.6(14.2) yrs;47% male 18–75 yrs;mixed sex 16–65 yrs;41–47%male 16–65 yrs;34% male 18–65 yrs;49% male 16–66 yrs;mixed sex
Description ofsample Patients con-sulting forLBP with oneof HMO’sprimary carephysiciansPatients con-sulting forLBP with oneof HMO’sprimary carephysiciansPatients from40 GP prac-tices in theNetherlands Working pa-tients from40 GP prac-tices in theNetherlands.(at index 64%were sicklisted)Patients re-ferred to anorthopaedicsurgeon forLBP withspecific causeof onset Cases identi-fied fromNationalMedicalInsurance filesin Norway
ued) Design andcohort Prospective,consecutivecases Prospective,consecutivecases Prospective,consecutivecases, RCT Prospective,presumablyconsecutivecases, RCT Retrospec-tive, consec-utive cases Retrospec-tive, preva-lent cases
n
Table 1 (conti Author, (year)country andquality score Dionne et al.(1995) [12],USA (samepopulation as[13] and [42]),83%Dionne et al.(1997) [13],USA (samepopulation as[12] and [42]),67%Faas et al.(1993) [16],The Nether-lands (studysample drawnfrom the samepopulation as[17]), 100%Faas et al.(1995) [17],The Nether-lands (studysample drawnfrom the samepopulation as[16]), 100%Greenough(1993) [19],Australia, 83% Hagen andThune (1998)[20], Norway100%
155
d
ne
uts er aver
o ge
Dropwereyounless scases
Point prevalence:90% of subjectswith history ofLBP in 1965 hadLBP during theyear prior toquestioningPain intensity(0–50) for acutecases: Index: 254 wks: 53 mths: 06 mths: 0and for subacutecases: Index: 214 wks: 53 mths: 76 mths: 5 Daily functioning(0–7) for acutecases: Index: 34 wks: 13 mths: 06 mths: 0and for subacutecases: Index: 24 wks: 13 mths: 16 mths: 0LBP at:4 wks: 70%8 wks: 48%12 wks: 35%1 yr: 10% Mediantime of recoveryfrom index epi-sode: 7 wks 76% experiencedrecurrencesSame as [23] andmedian durationof relapse: 3 wks 65% returned towork, 34% onlong-term dis-ability, 74% hadrecurrences
Pain Pain Disability Pain Recurrence Pain, recur-rence Sick leave
Pain or discom-fort in the lowerpart of the spine T12 to glutealfolds orradiatingtherefrom T12 to glutealfolds or radiat-ing therefrom T12 to glutealfolds or radiat-ing therefrom LBP of4–12 wks
History of LBP andX-rays at age 14and questionnaireat age 38 Monthlyquestionnaires for12 mths (incl. LBPdiary) Monthly question-naires for 12 mths(incl. LBP diary) Monthly question-naires for 12 mths(incl. LBP diary) 5 yrs, data frominsurance files
Index: 640;traced: 578;response: 481(83%) Index:443/603(73%);follow-up:269/443(61%) Index:443/603(73%);follow-up:269/443(61%) Index:443/603(73%);follow-up:269/443(61%) Controlgroup: 244;response ratenot applicable
e x x x s;e
% mal 6 yrs;xed se 6 yrs;xed se 6 yrs;xed se –65 yr% mal
46 >1mi >1mi >1mi 1861
All 14-year-old pupils in aDanish townin 1965 Patients con-sulting forLBP in 11 GPpractices inAmsterdamover 2 years Patients con-sulting forLBP in 11 GPpractices inAmsterdamover 2 years Patients con-sulting forLBP in 11 GPpractices inAmsterdamover 2 years,median dura-tion 10 days All patients ina Norwegiancounty ex-pected to take>8 weeks sickleave
Retrospec-tive, preva-lent cases Prospective,consecutivecases Prospective,consecutivecases Prospective,consecutivecases Prospective,consecutivecases, RCT
Harreby et al.(1996) [21],Denmark,100% van denHoogen et al.(1997) [22],The Nether-lands (samestudy as [23]and [24]),100% van denHoogen et al.(1997) [23],The Nether-lands (samestudy as [22]and [24]),100% van denHoogen et al.(1998) [24],The Nether-lands (samestudy as [22]and [23]),100% Indahl et al.(1998) [25],Norway, 83%
156
-
wers’ents y blue rs
Reviecomm Mainlcollarworke
Results 30% free of pain,49% sought treat-ment, 43% hadabsences, 12%received hospitalcare ~47% pain freeconsistently,~75% pain free at6 mths. No MS pain in1995: 12% withMS pain in 1996MS pain in 1995:52% with MSpain in 1996 34%of LBP cases in1995 persisted in1996OR (95% CI) incase of LBP in1978: 2.59(1.35–4.98) forLBP past year2.71 (1.74–4.21)for LBP previous7 yrs OR for developingLBP in case ofprevious LBP:2.2–5.6 31%reported LBPduring the year LBP during the3 yrs’ follow-upin case of LBP atindex: 93% versus39% for the restPrevalence ofcontinuous orrecurrent LBP atindex: 7.8%
)
Outcomemeasures Pain, sickleave, con-sultations Pain Pain Pain Pain (pastand present Pain
Description ofLBP Back or sciaticpain L1 to glutealfolds All MS paincombined, andLBP specifically Low backtrouble 12th rib to glute-al fold; any acheor pain >24 h LBP
Time & type offollow-up 1 yr after return towork or cessationof treatment bypostal question-naire 6, 12 and 18 mthsby questionnaire 1 yr by question-naire in class Questionnaire in1978. Postalquestionnaire in1993 for LBPprevious year andLBP past 7 years 12 mths, question-naire to peoplewho had not con-sulted for LBP 3 yrs by question-naire
Sample size& responserate Index: 936;follow-up:682/790(86%) 370–400/403,(92–99%) Index:1756/2116,(83%);follow-up:1628/1756(93%) 538/621(87%) 1540/2606(59%) 62/80 (78%)(31 matchedpairs)
Age &gender 18–65 yrs;97% male 18–39 yrs;92% female 9 or 11 yrs;mixed sex 45, 55 and65 yrs in1993; mixedsex 18–75 yrs;42% male 14 yrs atbaseline;47% male
Description ofsample Workers sicklisted fromthree indus-tries in north-ern England Healthcareworkerswithoutprevious“serious LBP” All pupilsfrom 3rd and5th grade in aFinnish town All inhabitantsin a Danishcounty bornin 1928, 1938and 1948,except the36 persons ondisabilitypension in1993 Patients at twoGP practicesin SouthManchester,who had notconsulted forLBP the prev-ious month1503 8th gradepupils fromFinland.Follow-up on40 with LBPat index and40 matchedcontrols
ued) Design andcohort Prospective,consecutivecases Prospective,inceptioncohort Prospective,prevalentcases Prospective,prevalentcases Prospective,prevalentcases Retrospec-tive, consec-utive cases
n
Table 1 (conti Author, (year)country andquality score Lloyd andTroup (1983)[27], UK(study sampledrawn from thesame popula-tion as [37]),67%Mannion et al.(1996) [28],UK, 100% Mikkelson(1997) [29],Finland, 67% Müller et al.(1999) [30],Denmark, 67% Papageorgiouet al. (1996)[31], UK(study sampledrawn from thesame popula-tion as [9] and[36]), 100%Salminen et al.(1995) [32],Finland, 83%
157
-
e
u
bl
y rs
Mainlcollarworke
Not functionallyrecovered at:index: 57%1 mth: 16%6 mths: 9%12 mths: 8%Not completelyrecovered at:index: 100%1 mth: 59%6 mths: 56%12 mths: 46%Sick-listed at:index: 43%1 mth: 3%6 mths: 3%12 mths: 2%Pain intensity(1–11): index: 5.11 mth: 4.63 mths: 3.512 mths: 2.5No recurrence(of sick leave):64%Two or morerecurrences: 11%Pain (1–6):index: 3.06 mths: 2.912 mths: 2.9 Still absent at:6 mths: ~40%12 mths ~25% Pain at:1 wk: 73%3 mths: 48%12 mths: 42%persistent (all 3):34% Absences:1st year: 44%2nd year: 31% Furthertreatment:1st year: 49%2nd year: 32%
e
Pain/dis-ability(functionalor completrecovery) Sick leave Pain Sick leaverecurrence Pain Sick leave Pain Sick leave Consulta-tions
Low back pain,<2 wks LBP w/wosciatica, sick-leave <2 wks Back pain w/woradiation 12th rib togluteal folds Back and sciaticpain
-
1, 6 and 12 mthsby postal questionnaire 1, 3 and 12 mthsby questionnaire 6 and 12 mths bysupervised ques-tionnaire. Sickleave by adminis-trative data 1 wk, 3 and 12mths by interview 1 and 2 yrs bypostal question-naire
503/524(96%) 123/180(68%) 131/186(70%);Control:77/95 (81%) Index:246/442;follow-up:180/246(73%) Year 1:503/802(87%); year2: 177/221(80%)
s;e s;e s;e s;e s;e
yral yral yral yral yral
0 m 4 m 6 m 5 m 0 m
–6% –6% –6% –7% –7%
82 93 94 81 87
16 15 14 14 19
Patientsconsulting130 GPs in aDanish county Consecutivepatientsreferred to anorthopaedicdepartment Consecutivecases ofsick-leave>8 weeks in aNorwegiancommunity Patientsconsulting forLBP during an18-monthperiod at twoGPs Patients sicklisted fromthree indus-tries in north-ern England
ctive,utive ctive,utiveRCT ctive,utiveRCT ctive,utive ctive,utive
ospensecses ospensecses, ospensecses, ospensecses ospensecses
roa roa roa roa roa
Pcc Pcc Pcc Pcc Pcc
Schiøtz-Christensen etal. (1999) [33],Denmark, 83% Seferlis et al.(1998) [34],Sweden, 100% Strøm andNilsen (1997)[35], Norway,83% Thomas et al.(1999) [36],UK (studysample drawnfrom the samepopulation as[9] and [31]),100%Troup andMartin (1981)[37], UK(study sampledrawn from thesame popula-tion as [27]),67%
158
Reviewers’comments Outcomebased onrecall of thepast 6 mths.Not com-parable tostudies ofpain at timeof interview Interventionunknown(no control)
Results Complaints at:0 follow-ups: 6%1 follow-up: 15%2 follow-ups: 23%all 3 follow-ups:57%LBP continu-ously: 10%At 1-yr follow-up:BP previous mth:Recent onset pa-tients (rop): 69%Prevalent patients(pp): 82%Painfree prev.6 mths: rop: 21%,pp: 12%BP>30 days prev.6 mths: rop: 26%,pp: 46%Poor/fair outcomerop: 24%,pp: 36%Pain 6/12 mths:78%/72%. Disability6/12 mths:26%/14%No participantsworsened fromindex to 12 mths50% return towork <8 wks and75% <18 wksMedian time toreturn to work:56 days28% of patientswith chronic and70% of those withacute LBP hadsubstantial relief45/76 applied fordisability pension
f
Outcomemeasures Pain anddisability Pain/dis-abilitycombined Pain Disability Sick leave Pain (dura-tion andfrequency osymptoms)and sickleave
Description ofLBP ICPC codes L03and L86 Current symp-toms >3 mthsBack pain Below T6 ona daily basis6–10 wks. Noprior episodes ofdaily pain Pain btnscapulae andgluteal folds;Sick leave<10 days LBP w/woradiation not dueto specific cause
n- e
Time & type offollow-up 4, 8 and 12 mthsby postal questionaire One yr byinterview 6 and 12 mths byinterview andorthopaedicexamination 3 and 12 mths byquestionnaire 2 yrs by telephoninterview
Sample size& responserate Index:368/524(70%);follow-up: ? Index:1213/1685(70%);follow-up:1128/1213(94%) Index:138/146(95%);12mths:76/138,(55%) 120;index: 117;3 mths: 110;12 mths: 108(90%) 80/99 (81%)
%
s;e s;e s; e3 s;e
Age &gender 20–60 yr51% mal 18–74 yr47% mal 18–50 yrall male Mean ag39 yrs; 3male 28–62 yr40% mal
Description ofsample Patients from26 GP prac-tices in theNetherlands Cross-sectionof back painpatients seenin primarycare in theSeattle area Patients at anaval medicalcentre Patients at8 occupationalhealth services All LBPpatients at arheumatologydepartment atGeneva Hospi-tal in 1993
ued) Design andcohort Prevalentcases Prospective,consecutivecases Prospective,inceptioncohort Prospective,consecutivecases Retrospec-tive, consec-utive cases
n
Table 1 (conti Author, (year)country andquality score Van Tulder etal. (1998) [38],The Nether-lands, 83% Von Korff etal. (1993) [42],USA (samestudy sampleas [12] and[13]), 67% Wahlgren(1997) [44],USA, 83% van der Weideet al. (1999)[45], TheNetherlands,83% Zufferey et al.(1998) [46],Switzerland,83%