This incredibly important article appears on the RSDSA Medical Articles Archive page, listed alphabetically by author - that's de Mos - under the heading "Research" at http://www.rsds.org/2/library/articl...ive/index.html

"The incidence of complex regional pain syndrome: A population-based study," M. de Mos, et al, Pain, May 2007, Vol. 129, Issue 1-2, pp. 12-20.

Here's the abstract:

The complex regional pain syndrome (CRPS) is a painful disorder that can occur in an extremity after any type of injury, or even spontaneously. Data on the incidence of CRPS are scarce and mostly hospital based. Therefore the size of the problem and its burden on health care and society are unknown. The objective of the present study was to estimate the incidence of CRPS in the general population. A retrospective cohort study was conducted during 1996–2005 in the Integrated Primary Care Information (IPCI) project, a general practice research database with electronic patient record data from 600,000 patients throughout the Netherlands.

Potential CRPS cases were identified by a sensitive search algorithm including synonyms and abbreviations for CRPS. Subsequently, cases were validated by electronic record review, supplemented with original specialist letters and information from an enquiry of general practitioners. The estimated overall incidence rate of CRPS was 26.2 per 100,000 person years (95% CI: 23.0–29.7). Females were affected at least three times more often than males (ratio: 3.4). The highest incidence occurred in females in the age category of 61–70 years. The upper extremity was affected more frequently than the lower extremity and a fracture was the most common precipitating event (44%). The observed incidence rate of CRPS is more as four times higher than the incidence rate observed in the only other population-based study, performed in Olmsted County, USA. Postmenopausal woman appeared to be at the highest risk for the development of CRPS. [Emphasis added.]

I had seen the abstract when it popped up a month ago on PubMed, but a graduate student friend was unable to get it off of his university computer system. The implications of the article are staggering, particularly where the insurance industry has been hiding behind a stricker list of "objective findings" in establishing the incidence of RSD in a given population. Significantly, the lastest study appears to have utilzed "reconfirmed diagnoses" as patients initial symtoms became more objectifiable over time.

On a personal note, the prior study done in 2002 in Olmsted Co., Minnesota, was by one of the doctors at the Mayo Clinic, who saw me in the Spring of 2002, roughly 9 months or so after I first developed pain, and declared that I didn't have RSD because of what was then a lack of objective findings. Her letter screwed me up for a long time in terms of getting disability coverage, even though I had already had a successful response to sympathetic nerve blocks. (Score one point for the insurance industry.)

Hopefully, the de Mos article, appearing as it does in Pain - a major journal - will go a long way to redress the damage done by the earlier work.

Mike

p.s. Please note that Frank Huygen, who is a joint author of the new study, has also produced a prodigious amount of work linking RSD/CRPS to immunologigal issues, specifically, pro-inflamatory cytokines. For one article that's been the subject of recent discussion on this page, please see "Increased endothelin-1 and diminished nitric oxide levels in blister fluids of patients with intermediate cold type complex regional pain syndrome type 1 J George Groeneweg," Frank JPM Huygen, Claudia Heijmans-Antonissen,Sjoerd Niehof and Freek J Zijlstra, BMC Musculoskeletal Disorders 2006, 7:91 doi:10.1186/1471-2474-7-91 and also available free of charge online online at http://www.biomedcentral.com/1471-2474/7/91