FROM: J Manipulative Physiol Ther. 2005 (Jul); 28 (6): 381–385 ~ FULL TEXT
Iben Axén, DC, Jess James Jones, MSc, Annika Rosenbaum, BAppSc(Chiro),
Peter W. Lövgren, DC, Laszlo Halasz, MHSc(ClinBiomech),
Kristian Larsen, PT, MPH, Charlotte Leboeuf-Yde, DC, MPH, PhD
The Medical Research Unit in
Ringkjøbing County, Denmark.
OBJECTIVE: The aim of this study was to develop a predictive model for treatment outcome in patients with low back pain (LBP) receiving chiropractic treatment.
METHODS: This multicenter practice-based predictive validity study was conducted in private chiropractic practices in Sweden. Of 64 previously compliant chiropractors, 58 recruited a maximum of 30 consecutive patients with LBP each. Information was provided on 1061 patients, of which 1057 questionnaires were valid. Chiropractic treatment was decided by the treating chiropractor. The outcome variable was the self-reported "definite improvement" at the fourth visit. The predictor variables included model 1, 3 hypothesized prognostic groups (best, intermediate, and least favorable) based on clinical information collected at baseline and at the second visit; and 4 additional models based on the following variables: age, sex, pain intensity during past 24 hours, description of disability, duration and pattern of pain during present attack, total duration of pain, and pain pattern during the past 12 months.
RESULTS: Three of our factors were best at predicting the absence of improvement by the fourth visit and were able to correctly classify 79% of patients and to cover 74% of the receiver operated characteristics curve. These were
(1) no definite overall improvement by the second treatment,
(2) presence of leg pain, and
(3) the minimum total duration of pain over the last 12 months being 30 days.
CONCLUSION: In this study, patients with LBP who also had leg pain and LBP occurring sufficiently frequently or having lasted sufficiently long to add up to at least 30 days in the past year, and who did not report definite general improvement by the second treatment were not good candidates for short-term recovery. It is suggested that patients who fit the criteria of potential nonresponders should be carefully monitored to allow a selective approach of care.
From the FULL TEXT Article:
Clinical experience can be defined as the knowledge gathered by treating many patients. Theoretically, the clinician's mind will link a patient's history and examination findings with treatment outcome, so that when experienced, he is able to accurately select patients who are likely to benefit from various types of treatment. Groups of clinicians in Norway and Sweden have attempted to validate these “gut feelings.”
In the Norwegian study,  only 5 factors of 70 mainly clinical factors were found to be predictive of favorable short-term treatment outcome in patients with persistent low back pain (LBP), namely, sex, receivers of social benefit, severity of pain, duration of pain, and presence of neck pain. The remaining 65 variables thought to be predictive did in fact contribute only to noise, that is, clouding the picture. In addition, status at the fourth visit was a predictor for outcome both at 3 months and 12 months.
In the first of the Swedish studies,  3 predictor profiles were constructed for chiropractic patients with persistent LBP. For the first of these profiles, a good fourth visit outcome was expected and was found for these patients. This model consisted of the 4 following characteristics:
immediate improvement reported while still in the treatment room,
improvement by the second visit,
a common reaction (local pain and/or tiredness for less than 24 hours) or
no reaction to treatment, and reduced disability of at least one parameter (as described later), by the second visit.
A poor fourth visit outcome was expected for patients with all of the 4 following characteristics:
no immediate improvement directly after treatment,
no improvement by the second visit,
an uncommon reaction (local pain and/or tiredness for more than 24 hours or a new radiating pain)
or no reaction to treatment, and no reduced disability by the second visit.
For patients not fitting into any of the previous two profiles, the outcome was expected to lie in between the first two groups. The model was found to be valid  and later confirmed to be operational in a study of patients with nonpersistent LBP. 
Some of the variables found to predict short-term treatment outcome in the previous studies can be identified after treatment, whereas others consist of information that can be collected by a receptionist already at the time of making the appointment. This leads to the provoking thought that clinical judgement and experience may be replaced by some simple standard questions, not requiring a clinical encounter. It also appears that, if treatment is commenced, prediction of short-term treatment outcome is already possible by the second visit.
It was the purpose of the present study to investigate whether we could refine the Swedish model to provide a prognostic instrument to be used on all patients with LBP seeking care in chiropractic practice.
It was not the purpose of this study to investigate rates of improvement but to study predictors of improvement. The results of the present study have taught us two things.
First, it is possible to predict short-term outcome in patients with LBP who receive chiropractic care.
Second, adding more information does not automatically improve this ability.
Obviously, it is important to keep in mind the weaknesses of this type of study design, such as several possibilities for bias in relation to selection of practitioners and patients, in relation to their expectations of treatment outcome, and in relation to the recording of outcome. With these limitations in mind, however, we conclude that it is possible for chiropractors to predict short-term outcome in patients with LBP already before treatment commences and, at the latest, by the second visit. Short-term outcome (ie, recovery by the fourth visit) has already been shown to be a predictor for long-term outcome at both 3 and 12 months. 
It is therefore recommended that chiropractors incorporate this information in their clinical practice and that they become aware of its possible implications. Patients who fit the criteria of potential nonresponders should be carefully monitored to allow a selective approach of care. After all, what patients expect from their chiropractors is not only that treatment can help improve their condition but also that chiropractors refrain from treating patients with little or no hope of getting better.
Therefore, patients with LBP who also have leg pain, with LBP occurring sufficiently frequently or having lasted sufficiently long to add up to at least 30 days in the past year, and who do not report definite general improvement by the second treatment are not obvious candidates for short-term recovery. Continued care should be monitored carefully because short-term outcome is a predictor for long-term outcome. 
More work is needed in this area, for example, to find out whether this predictive profile is similar for other types of therapies and if it is perhaps simply a profile of nonimprovement also in people who do not receive care.
Leboeuf-Yde C, Gronstvedt A, Borge JA, Lothe J, Magnesen E, Nilsson O, et al.
The Nordic Back Pain Subpopulation Program: Demographic and Clinical Predictors for Outcome
in Patients Receiving Chiropractic Treatment for Persistent Low–Back Pain
J Manipulative Physiol Ther. 2004 (Oct); 27 (8): 493–502
Axen I, Rosenbaum A, Robech R, Larsen K, Leboeuf-Yde C.
Can Patient Reactions to the First Chiropractic Treatment Predict Early Favorable Treatment Outcome
in Nonpersistent Low Back Pain?
J Manipulative Physiol Ther. 2002 (Sep); 25 (7): 450–454
Axen I. et al.
The Nordic Back Pain Subpopulation Program: Can Patient Reactions to the First Chiropractic Treatment
Predict Early Favorable Treatment Outcome in Nonpersistent Low Back Pain?
J Manipulative Physiol Ther. 2005 (Mar); 28 (3): 153–158
Leboeuf-Yde, C, Axén, I, Ahlefeldt, G, Lidefelt, P, Rosenbaum, A, and Thurnherr, T.
The types and frequencies of improved nonmusculoskeletal symptoms reported after chiropractic spinal manipulative therapy.
J Manipulative Physiol Ther. 1999; 22: 559–564
Leboeuf-Yde, C, Hennius, B, Rudberg, E, Leufvenmark, P, and Thunman, M.
Side effects of chiropractic treatment: a prospective study.
J Manipulative Physiol Ther. 1997; 20: 511–515
Altman DG, Machin D, Bryant TN, Gardner MJ, editors.
Statistics with confidence. 2nd ed. Bristol:
BMJ Book, JW Arrowsmith Ltd; 2002. p. 111-6.