Rates Of Lower Back Surgery Vary To 20-Fold, Ten-Year Review Finds
Main Category: Bones / Orthopaedics News
Article Date: 06 Nov 2006 - 0:00am (PST)
http://www.medicalnewstoday.com/medi...p?newsid=55859
Study Shows Wide Regional Variations in Spinal Surgery Rates of Lower Back Surgery Vary to 20-Fold, Ten-Year Review Finds Newswise - Rates of lower back surgery among older adults-especially for an increasingly frequent procedure called lumbar fusion-vary widely across different regions of the United States, reports a study in the Nov. 1 issue of Spine (http://www.spinejournal.com).

Although the study can't explain the reasons for the variation, the findings raise concerns about the quality of the scientific evidence on back surgery in general and lumbar fusion in particular, according to a research group from Dartmouth Medical School. The lead author was Dr. James N. Weinstein, Chairman of Orthopaedic Surgery and Professor in Community & Family Medicine and Senior member of the Center for the Evaluative Clinical Sciences at the Dartmouth-Hitchcock Medical Center and Dartmouth Medical School. Dr. Weinstein is also Editor-in-Chief of Spine, the leading peer-reviewed journal on the study of the spine.

The researchers analyzed nationwide data on rates of lumbar spine (lower back) surgery among Medicare recipients aged 65 and older, between 1992 and 2003. The results showed a dramatic increase in spinal surgery during this time-in 2003, Medicare spent over $1 billion on spinal surgery.

There was a particularly sharp increase in the rate of lumbar fusion surgery-an operation performed to fuse adjacent vertebrae together-after the introduction of a new surgical implant device in the mid-1990s. The average rate of lumbar fusion doubled from 0.3 to 1,000 Medicare enrollees in 1993 to 0.6 per 1,000 in 1998, increasing further to 1.1 per 1,000 enrollees in 2003. As a percentage of total Medicare spending for back surgery, lumbar fusion increased from 14 percent in 1992 to 47 percent in 2003.

The study also found wide variation in rates of lower back surgery among Medicare recipients living in the 306 different U.S. hospital referral regions. Rates of lumbar discectomy and laminectomy-procedures commonly performed for patients with disc-related back problems-varied 8-fold across regions. For spinal fusion, the variation was even greater-20 times higher in some regions than others. This was much larger than the variation for other major operations in older adults, such as hip replacement or surgery for hip fracture.

Regions with lower rates of back surgery in the 1992-93 tended to have low rates in 2002-03 as well. The variations were unrelated to the regional supply of orthopedic surgeons and neurosurgeons. Regions with high rates of spinal fusion included Idaho Falls, Idaho, Missoula, Mont., and Mason City, Iowa. The lowest rates were found in Bangor, Maine, Covington, Ky., and Terre Haute, Ind.

The study permits no conclusions about why the variations in back surgery rates are so high-likely contributors include "lack of scientific evidence, financial incentives and disincentives to surgical intervention, and differences in clinical training and professional opinion," the authors believe. The variation is unlikely to be related to patient preferences; rates sometimes vary substantially even for neighboring, demographically similar regions.

Dr. Weinstein and his fellow researchers voice concern about the quality of research evidence regarding back surgery, particularly lumbar fusion. "The scientific evaluation of outcomes for spine surgery has not kept up with the changes in operative techniques," they write.

In the absence of high-quality research, "Major surgery is often conducted without an adequate scientific basis for making a reasonably accurate estimate of the likely outcomes," Dr. Weinstein and colleagues write. They urge redoubled efforts at effective assessment of medical technologies, concluding, "The mobilization of talent and focus of interest required to meet the larger task of improving the scientific basis of everyday practice will require the active participation of the funding agencies and academic medical centers."

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What really works? Study hopes to solve back-pain conundrum

In spite of the fact that back pain is one of the most common ailments in modern society, there is little evidence about how best to diagnose and treat it. A new study directed by James Weinstein, D.O., M.S., medical director of DHMC's Spine Center, promises to answer at least part of the back-pain conundrum: are non-surgical treatments as successful as back surgery?

Funding: The study, called SPORT (Spine Patient Outcomes Research Trial), is supported by a $14.5-million grant from the National Institutes of Health, one of the largest grants ever awarded to DMS.

According to the Dartmouth Atlas of Health Care, the likelihood that a Medicare enrollee will undergo surgery for back pain varies by a factor of six— from 1.4 per 1,000 enrollees in the Bronx, N.Y., to 8.6 per 1,000 in Bend, Ore. What accounts for the differences? Researchers are convinced it isn't varying rates of disease. "We believe it's more a question of where you live and what doctor you consult," Weinstein says, "and that the differences we see reflect regional differences in medical opinion about what works."

The Dartmouth-led study expects to enroll 1,450 patients (between 200 and 300 of them at DHMC) at 11 medical centers nationwide. The patients will be randomized to receive either surgical or nonsurgical treatment. Nonsurgical options include bed rest, physical therapy, exercise, injections, oral anti-inflammatory drugs, and other non-narcotic medications.

The primary criteria for participation in the study are diagnoses of herniated disc, spinal stenosis, or degenerative spondylolisthesis; symptoms of low-back pain radiating into the buttock, thigh, or leg on walking or sitting; or loss of sensation or weakness in the leg. Those who have had previous back surgery and pregnant women will be excluded from the study.

The researchers will then collect data on participants' health status, ability to function, satisfaction with their health, and subsequent utilization of healthcare services. In addition, an attempt will be made to estimate the direct and indirect costs of each case of back pain (indirect costs include such things as days of missed work). The goal is to develop a cost-benefit ratio: how much does alleviating back pain cost and which treatment gives better "bang for the buck," according to Weinstein, a professor of surgery at DMS.


Satisfaction: Because not all patients will want to be randomized, an additional 1,800 will be allowed to make their own treatment choices but will be followed similarly. Data on how satisfied patients are with a choice they've made themselves can then be compared to satisfaction among randomized patients.

Weinstein—whose general reluctance to treat back pain surgically is reflected in the relatively low rate of back surgery locally (2.1 per 1,000 Medicare enrollees, compared to a national average of 3.1)—is also director of DHMC's Center for Shared Decision-Making. There, patients can get information about their condition, data about the likely outcomes of various treatment options, and support for being part of a decision-making team with their doctors.

"We're trying to help patients become better consumers of health care," says Weinstein, "by giving them enough information that they can participate in decision- making in an informed way. SPORT will give us valuable information about the outcomes of back surgery, so that people with low-back pain can make choices based on the best scientific evidence of . . . what the trade-offs are among the various treatment options."

The remarkable thing about the SPORT study was that even after patients agreed to participate in the study and be randomized to either surgery or conservative treatment, they left the group they were assigned to in large numbers.

Those assigned to conservative treatment, if they felt their pain was unbearable, switched to surgery, and those in the surgery group, feeling they could tolerate their pain, switched to conservative treatment.

So in the end, while both groups did the same--people tended to heal well from disk-caused sciatica--the study ended up showing that people in severe pain, choosing surgery, do well; and people in less pain, choosing to avoid surgery, do well.

That people refused to stay randomized based on their pain was interesting, in itself. It mimicked life more than the researchers expected.