Acute Lower Back Problems in Adults - Costs

Evaluating Harms.

Since back problems are rarely life–threatening, the panel paid special attention to potential harms (side effects or complications) of assessment and treatment methods. Controlled trials evaluating treatment and assessment methods, however, seldom included enough subjects to detect rare but potentially serious complications. This information was found only in large case series or case reports. On the other hand, controlled trials of oral medications often included extensive information on side effects. Thus, accurate comparison of the relative risks of side effects and complications of different assessment and treatment methods was not possible.

A lack of published evidence about harms related to specific treatment or assessment methods does not mean that potential harms do not exist. In many instances, the side effects and complications of assessment and treatment methods have never been extensively studied or comprehensively reported. In addition, articles evaluating newer treatment and assessment methods are often written by advocates of these methods, who may tend to deemphasize the harms.

The panel felt it was important for both clinicians and patients to have a sense of potential harms relative to the potential benefits of these methods. Therefore, the panel considered information about potential harms from a variety of sources, including case series, case reports, cross–sectional surveys, clinical trials, and in some instances studies of patients who did not have low back problems. Finally, if no specific information was available from any of these sources, the panel generally considered whether the method was invasive or carried the potential for an allergic reaction.

Evaluating Costs.

Both clinicians and patients need to consider relative costs of assessment and treatment methods before making informed decisions about care. Costs vary greatly, however, and the cost data on assessment and treatment methods for low back problems are limited. The unit cost of a service may vary within and between geographical regions. The aggregate cost of services also varies depending on the frequency and duration of services for the individual patient. Although costs of various medical services have generally increased in recent years, they have done so at inconsistent rates. Given these variations, the panel decided to make broad statements about whether methods appeared to be of low, moderate, or high cost, graded according to the following system (based on 1993 dollars):

• 1. Low cost: under $200.
• 2. Moderate cost: $200 to $1,000.
• 3. High cost: over $1,000.

This grading system provides no more than a rough comparison of costs, and the panel recognized that the divisions between cost categories are somewhat arbitrary. For example, some Americans may not consider a $199 expense that comes directly out of pocket to be "low cost."

Developing the Guideline Recommendations

To develop recommendations for each assessment and treatment method, the panel considered: (1) the quality and amount of evidence for efficacy, (2) the strength of the effect found for the method, (3) the consistency of findings between studies, (4) the clinical applicability of the evidence to adult patients with acute low back problems, and (5) any evidence on harms or costs. For each assessment and treatment method the panel then sought to answer the following questions:

• 1. What is the likelihood that this assessment or treatment method will:
  o Benefit the patient?
  o Harm the patient?
  
• 2. Does the likelihood and magnitude of potential benefit outweigh the likelihood and magnitude of potential harm enough to justify the cost for this method?

The development of findings and recommendations statements required the collective judgment of the panel in interpreting the available evidence. The panel rated the amount and quality of evidence supporting each guideline statement using the scale in the Figure <http://text.nlm.nih.gov> below.

Panel ratings of available evidence supporting guideline statements

A. = Strong research–based evidence (multiple relevant and high–quality scientific studies).
B. = Moderate research–based evidence (one relevant, high–quality scientific study or multiple adequate scientific studies <http://text.nlm.nih.gov>).
C. = Limited research–based evidence (at least one adequate scientific study in patients with low back pain).
D. = Panel interpretation of information that did not meet inclusion criteria as research–based evidence.

*Met minimal formal criteria for scientific methodology and relevance to population and specific method addressed in guideline statement.

This rating system (A, B, C, or D) is the basis for:

Recommendations for: If the available evidence indicates that potential benefits outweigh potential harms.

Options: If the available evidence of potential benefits is weak or equivocal (inconsistency in some studies) but potential harms and costs appear small.

Recommendations against: If the available evidence indicates either a lack of benefit or that potential harms and costs outweigh potential benefits.

The guideline's findings and recommendations statements therefore represent the panel's assessment of a method's potential to achieve the intended assessment or treatment goals, balanced against its potential harms and costs.

Bigos S, Bowyer O, Braen G, et al. Acute Low Back Problems in Adults.
Clinical Practice Guideline No. 14. AHCPR Publication No. 95–0642.
Rockville, MD: Agency for Health Care Policy and Research, Public Health
Service, U.S. Department of Health and Human Services. December 1994.