FORCES - COVER-UP: NON-SMOKING IS A RISK FOR THROMBOEMBOLISM

There has recently been a resurgence of medical interest in the subject of postoperative thromboembolism. Surgery and immobilization can precipitate deep venous thrombosis, and the clot can break loose and lodge in the lung. There is excess risk for a month or more afterwards. The leg is the most frequent source of the clot.

There are about 170,000 episodes of venous thromboembolism, 90,000 of them recurrent in the US every year (FA Anderson Jr, HB Wheeler, RJ Goldberg, DW Hosmer, A Forcier, NA Patwardhan. Ann Intern Med 1991;115;591-595).

In the UK, 10% of all hospital deaths are due to pulmonary embolism (Thromboembolic Risk Factor (THRIFT) Consensus Group. BMJ 1992 Sept 5; 305:567-574).

Recent studies say nothing about the effects of smoking. Smoking does not appear on any of their list of risk factors. In fact,
between 1974 and 1980, it was discovered, to everybody's surprise, that non-smokers were at considerably greater risk for deep venous thrombosis. This was discussed in the British Medical Journal, then the subject mysteriously disappeared, without attracting attention in the US.

Is it too emotionally and politically unacceptable for the anti-smoking establishment to admit the truth? It seems they would rather say nothing at all, than to admit that smoking is not a risk factor, let alone that non-smoking is one. Here are the studies they refuse to talk about:

Handley AJ, Teather D. Influence of smoking on deep vein thrombosis after myocardial infarction. RMJ 1974 Jul 27;3:230-231. 17/61 (28%) of smokers, 19/37 (51%) of nonsmokers developed DVT. Excluding high-risk, 7/38 (18%) of smokers, 9/22 (41%) of nonsmokers did.

Marks P, Emerson PA. Increased incidence of deep vein thrombosis after myocardial infarction in nonsmokers. BMJ 1974 Jul 27;2:232-234. Among non-anticoagulant treated patients, 7/65 (11%) of smokers vs. 23/37 (67%) of nonsmokers developed deep-vein thrombosis. Excluding those at high risk, 13/25 (52%) of nonsmokers and 3/56 (5.4%) of smokers. (Also, the nonsmokers were lighter than the smokers).

Clayton, JK, Anderson JA, McNicol GP. Preoperative prediction of postoperative deep vein thrombosis. BMJ 1976 Oct. 16;2:910-912. 5/55 (9.1%) of smokers vs 15/69 (22%) of nonsmokers were positive (gynaecologic surgery).

Pollock AV, Evans M. (letter) Cigarette smoking and postoperative deep-vein thrombosis. BMJ 1978 Aug. 26;2:637. 10/52 (19.2%) of cigarette smoker, 7/17 (41.2%) of pipe smokers, 35/97 (36.1%) of nonsmoker laparotomy or prostatectomy patients developed DVT. "Although it may be true that cigarette smokers are younger and thinner than nonsmokers, that is certainly not the whole explanation of the protective effect of this otherwise undesirable [sic] habit."

Bucknall TE, Bowker T, Leaper DJ. Does increased movement protect smokers from post-operative deep vein thrombosis? BMJ 1980 Feb 16;280:447. In 40 inguinal herniorrhaphy patients, differences in amount of movement were not significant.

Kierkegaard A, Norgren L, Olsson C-G, Castenfors J, Persson GS. Incidence of deep vein thrombosis in bedridden non-surgical patients. Acta Med Scand 1987;222:409-414. 1/12 = 8% smokers, 12/89 = 13% non-smokers positive for DVT, nonsignificant.

Only a single study did not confirm these findings:

Hayes MJ, Morris GK, Hampton JR. Lack of effect of bed rest and cigarette smoking on development of deep venous thrombosis after myocardial infarction. Br Heart J 1976;38:981-983. 28/113 (25%) s, 14/69 (20%) n positive.

"Venous thrombosis lenghtens the staying of patients undergoing general surgery by seven days," increasing the costs by $2005 in 1984 dollars (G Oster, RL Tuden, GA Colditz. Prevention of venous thromboembolism after general surgery. Cost-effectiveness analysis of alternative approaches to prophylaxis. Am J Med 1987 May;82:889-899).

Anti-smoker publicists openly wish to claim that smokers' hospitalization costs are greater than non-smokers', to run up the economic cost of smoking, but little has come of it in the light of truth. Perhaps they discovered to their dismay that the truth was not on their side. The Oster study may be the salvaged remains of such an attempt.

Routine prophylaxis of surgical patients with anticoagulants has been recommended to decrease thromboembolism. But this may cause more risks than it would prevent in low-risk patients. Smokers' lives would be needlessly jeopardized if they are treated under the assumption that their risk is the same as non-smokers', or worse, if they are more likely to be treated in the false belief that they are at greater risk because they smoke. And non-smokers are jeopardized if they are assumed to be safe.

How many people have died as a result of this anti-smoker mentality? It is, frankly, impossible to judge. The utter scientific irresponsibility promulgated by this mindset has a potential for endless repercussions -- economically, socially and medically.

Courtesy of Carol Thompson 08/23/93
Smokers' Rights Action Group
P.O. Box 259575
Madison, WI 53725-9575
Phone: 608-249-4568