Low Back Pain & Sciatica(Prognostic Factors & Outcome)

Alaa Eddeen AlQaisi, MDPHCI 611-01 - Fall 2014

I- Epidemiological Facts

• Low back pain is one of the most common health problems and creates asubstantial personal, community, and financial burden globally.

• LBP is a major cause of disability - affecting performance at work andgeneral well-being.

• LBP affects people of all ages, from children to the elderly, and is a veryfrequent reason for medical consultations.

• The 2010 Global Burden of Disease Study estimated that LBP is among thetop 10 diseases and injuries that account for the highest number of DALYsworldwide.

Disability-Adjusted Life Year (DALY)??

• One DALY one lost year of "healthy" life measurement of the gap between current health status and an ideal health situation.

DALYs for a disease or health condition are sum of the Years of Life Lost (YLL) due to premature mortality and the Years Lost due to Disability (YLD) for people living with the health condition in a population.

Absolute DALYs caused by low back pain by age group and European region

Prevalence:

• The lifetime prevalence of non-specific LBP is estimated at 60% to 70% in industrialized countries (one-year prevalence 15% to 45%, adult incidence 5% per year).

(Over 70% of people in resource-rich countries develop LBP at some time)

• The prevalence rate for children and adolescents is lower than that seen in adults but is rising.

• Prevalence peaks between the ages of 35 and 55

• In the United Kingdom, low back pain was identified as the most common cause of disability in young adults, with more than 100 million workdays lost per year

• In Sweden, a survey suggested that low back pain accounted for a quadrupling of the number of work days lost from 7 million in 1980 to 28 million by 1987.

LBP in USA

• Episodes of LBP, that are frequent or persistent have been reported in15% of the US population.

• Lifetime prevalence of 65% to 80%.

• 28% of the US industrial population will experience disabling LBP at sometime & 8% of the entire working population will be disabled in any givenyear, contributing to 40% of all lost work days.

• Morbidity & mortality of occupational injury or illnesses in the USshowed that the total direct costs ($65 billion) plus indirect costs ($106billion) were estimated to be $171 billion, with injuries costing $145billion and illnesses $26 Billion.

Low back pain ranks No. 1 in musculoskeletal disorders.Modified and adapted from Lawrence and colleagues

Risk Factors

• age

• Genetic

• Gender ???

• obesity, body height

• occupational posture

• frequent bending, twisting

• heavy physical work

• Whole body vibration

• depressive moods

II – Topic Articles Review:

Haugen, A. J., Brox, J. I., Grøvle, L., Keller, A., Natvig, B., Soldal, D., & Grotle, M. (January 01, 2012). Prognostic factors for non-success in patients with sciatica and disc herniation. Bmc Musculoskeletal Disorders, 13.

Peul, W. C., Brand, R., Thomeer, R. T., & Koes, B. W. (January 01, 2008). Influence of gender and other prognostic factors on outcome of sciatica. Pain, 138, 1, 180-91.

Haugen et al., Prognostic factors for non-success in patients with sciatica and disc herniation – Study (1)

• Study Design: Prospective multicenter Cohort study.

• Main Variables measured:

1- socio-demographic characteristics

2- back pain history

3- kinesiophobia

4- emotional distress

5- pain

6- comorbidity

7- clinical examination findings.

• Cohort Selection and Recruitment:

1- Patients were recruited from specialty back clinics at 4 public hospitals in Southeast Norway.

2- inclusion period was 2 years, throughout 2005 and 2006.

• Inclusion criteria:

i. age ≥18 years

ii. radiating pain and/or paresis below knee level

iii. disc herniation at the corresponding level and side that had been verified by (MRI) or (CT).

• Exclusion criteria:

i. Prior surgery at the same disc level.

ii. Fracture

iii. Infection

iv. Malignancy

v. Pregnancy

vi. Lack of fluency in Norwegian.

• Procedure:

At the day of inclusion patients completed a comprehensivequestionnaire. Baseline data were collected at the first visit to thedepartment. Clinical examination was conducted by a physician orphysiotherapist. A follow-up questionnaire and a prepaid envelopewere sent to the patients after 3, 6,12 and 24 months. A reminderwas sent after 2 weeks if no reply was obtained.

In each questionnaire, the participants were asked whether they hadundergone surgery for disc herniation in the period since the lastfollow-up period, and if so, the patient reported the date of surgery.

Outcome measure and definition of non-success

1- Maine–Seattle Back Questionnaire (MSBQ) was the main outcome measure.

• The scale is composed of 12 items

• each with the answer yes (1) or no (0).

• The MSBQ assesses disability and functional limits due to sciatic and back pain, and higher scores indicate worse limitations on activity.

• Non-success was defined as a MSBQ score ≥ 5

2- Siatica Bothersomeness Index (SBI) is the secondary outcome measure was the Sciatica.

• SBI is a composite of the scores for four symptoms: leg pain (sciatica); numbness or tingling in the leg, foot or groin; weakness in the leg or foot; and back or leg pain while sitting.

• Nonsuccess was defined as a SBI score of ≥ 7

Outcomes: 466 patients were included.

409 (88%) responded to the 1-year follow-up questionnaire.

380 (82%) responded to the 2-year follow-up questionnaire.

Among the responders at 1 year, 120 (29%) had received surgical treatment.

At 2 years, 120 (32%) of the responders were recorded as surgically treated.

For patients who were operated, surgery was performed within 3 months of follow-up for 81% of the patients.

Patients with non-success (MSBQ ≥ 5) numbered 178 patients (44%) at 1 year and 145 (39%) at 2 years.

Outcomes (Cont’d):

the surgically treated patients, 42 (35%) had non-success at the 1-year follow-up, and 47 (39%) had non-success at the 2-year follow-up.

the non-surgical group, 136 (47%) and 98 (39%) patients had non-success at 1 and 2 years respectively.

Results:

1) 44%–47% of the patients with sciatica who were referred for secondary care had a non-successful outcome at 1 year and 39%–42% at 2 years.

2) Approximately 1/3 of the patients were treated surgically.

3) For the main outcome variable, non-success at 1 year was significantly associated with being male (OR 1.70 [95% CI; [1.06 − 2.73]), smoker (2.06 [1.31 − 3.25]), more back pain (1.0 [1.01 − 1.02]), more comorbid subjective health complaints (1.09 [1.03 − 1.15]), reduced tendon reflex (1.62 [1.03 − 2.56]), and not treated surgically (2.97 [1.75 − 5.04]).

4) factors significantly associated with non-success at 2 years were duration of back problems > 1 year (1.92 [1.11 − 3.32]), duration of sciatica > 3 months (2.30 [1.40 − 3.80]), more comorbid subjective health complaints (1.10 [1.03 − 1.17]) and kinesiophobia (1.04 [1.00 − 1.08]).

5) For the secondary outcome variable, more comorbid subjective health complaints, more back pain, muscular weakness at clinical examination, and not treated surgically, were independent prognostic factors for non-success at both 1 and 2 years.

Peul et al., Influence of gender and other prognostic factors on outcome of sciatica Study (2):

• Research Question:

• Female gender has been found to be associated with chronic pain in other musculoskeletal disorders.

• The study aim is to quantify the relationship between gender and

(1) rate of recovery

(2) outcome at one year

Design:

• Randomized Multicenter Trial• Patients were allocated randomly to either a prolonged conservative care,

possibly with late surgery, or early surgery preferably within two weeks.

Inclusion Criteria:

• 283 patients who suffered sever sciatica were enrolled

• age 18 – 65 years old

• had a radiologically confirmed disk herniation

• incapacitating lumbosacral radicular syndrome lasting between 6 and 12 weeks

Exclusion Criteria:

1. cauda equina syndrome

2. muscle paralysis or insufficient strength to move against gravity

3. Patients had had identical complaints in the past twelve months

4. history of spinal surgery

5. bony stenosis

6. Pregnancy

7. severe comorbidity

Outcomes:

• Follow-up of patients at 2, 4, 8, 12, 26, 38 weeks and at one year was recorded.

• A 7-point Likert global perceived recovery scale, patient experienced recovery compared to baseline, with answers ranging from completely recovered to much worse.

• Roland Disability Questionnaire (RDQ) for Sciatica

• Horizontal Visual Analogue Scale (VAS-leg) recording the individually experienced intensity of pain

Results:

• Allocation of an early surgical strategy resulted in 125 of 141 (89%) patients who actually underwent lumbar discectomy after a median period of 1.9 weeks.

• while of the 142 conservatively managed patients surgery could not be avoided in 55 (39%) after a median time of 14.6 weeks.

• At different follow-up moments during the first year 269 of 283 (95%) patients registered complete recovery.

• At exactly 12 months, however, 83% of patients reported complete recovery

• (34%) of 283 patients were female.

Results (Cont’d):

• Results at 12 months showed a significantly different outcome between genders with 28% of females exhibiting an unsatisfactory perceived outcome versus 11% of males??

• Women had a slower rate of recovery: HR 0.76 (95% CI 0.59–0.99) with an unsatisfactory outcome represented by an unadjusted odds ratio of 3.3 (95% CI 1.7–6.3) compared to males. Besides a slower recovery rate, female gender was a strong predictor of unsatisfactory outcome at one year for patients with sciatica

Conflicting Findings

Haugen et al.,

• Non-Success 44%–47% at One Year, 39%–42% at 2 years.

• Non-success at 1 year was significantly associated with being male (OR 1.70) .

Peul et al.,

• (95%) patients registered complete recovery, at 12 months (83%) of patients reported complete recovery.

• Women had unsatisfactory outcome represented by an unadjusted (OR 3.3)compared to males.

Discussion & possible explanation of conflicting findings:• The 2 studies had different Designs, Haugen et al Prospective Cohort,

Peul et al Randomized Trial, randomization procedure wasn’t stated in the article.

• Haugen et al enrolled 466 participants, Peul et al enrolled 283 participants (Bigger sample size in Haugen et al more precision in results?)

• Haugen et al Followed patients for 2 years, Peul et al followed patients for 1 year (Longer time of follow up, better assessment of association between predictor variables & outcome variables).

• Exclusion Criteria in Peul et al were duration of sciatica symptoms of more than 12 weeks, similar complaints during the previous year, or severe comorbidity, therefore Haugen et al was probably more representative of the majority of patients with sciatica and disc herniation.

• Haugen et al used the most precise outcome measures, which in a previous study showed the highest sensitivity and specificity to discriminate between successful outcome or not for sciatica patients.

• Haugen et al had a broader range of prognostic variables including several clinical findings, psychological variables and comorbid subjective health complaints.

• The success rates and prognoses for sciatica vary between studies, depending on the inclusion criteria and outcome measures used.

Refrences:1. Haugen, A. J., Brox, J. I., Grøvle, L., Keller, A., Natvig, B., Soldal, D., & Grotle, M.

(January 01, 2012). Prognostic factors for non-success in patients with sciatica and disc herniation. Bmc Musculoskeletal Disorders, 13.

2. Peul, W. C., Brand, R., Thomeer, R. T., & Koes, B. W. (January 01, 2008). Influence of gender and other prognostic factors on outcome of sciatica. Pain, 138, 1, 180-91.

3. Hall, Hamilton, & McIntosh, Greg. (n.d.). Low back pain (chronic). BMJ Publishing Group.

4. Manchikanti, Laxmaiah, et, al. “Epidemiology of Low Back Pain”. Pain Physician Vol. 3, No. 2, 2000.

5. Duthey, Béatrice. “Background Paper 6.24 - Low back pain”. Priority Medicines for Europe and the World "A Public Health Approach to Innovation“ Update on 2004 Background Paper (15 March 2013). WHO.

THANK YOU!

Alaa Eddeen AlQaisi, MDPHCI 611-01 - Fall 2014