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POST-ABORTION CHLAMYDIAL PELVIC INFECTION
1219
POST-ABORTION CHLAMYDIAL PELVIC INFECTION
SIR,-We agree with Mr Wood and Dr Muscat (Oct 14, p 928) that Chlamydia trachomatis is a frequent isolate from the cervices of women requesting termination of pregnancy. We have done endocervical swabs on 1874 consecutive outpatients seeking pregnancy termination between 1985 and 1988. C trachomatis was detected in 155 patients and Neisseriagonorrhoeae in 3, 1 of whom also harboured chlamydia. The overall infection rate for these two organisms was 8 33%. 71 % of women were single and in these the infection rate was 9-75%, significantly higher than that for married or previously married women (relative risk 240; 95% confidence intervals [CI] 136, 4-22). The rates for married, divorced, or separated women were 4-3%, 6-3%, and 5-7%, respectively. Single women under the age of 25 had the highest rate—10-2% (relative risk 1 -95,95% CI 1 -35,2-80). Nulliparous patients with a previous spontaneous or induced abortion had a lower rate of infection than primigravid patients (7-6% compared with 9-2%). Scandinavian studiesm3 have shown that the frequency of post-abortal endometritis or salpingitis was 20-28% where C trachomatis was isolated in the cervix before termination. In two of these investigations younger patients with endocervical chlamydia had an even greater risk of post-abortal infection. In the short term, post-abortal pelvic infection may mean extra patient time in hospital. Treatment of chlamydia-positive women reduces the frequency of post-abortal infection.’ The long-term sequelae are more uncertain. Despite Westrom’s reports that at least 12-8% of women are infertile after one episode of laparoscopically proven pelvic infection, epidemiological studies have not demonstrated an increased risk of secondary subfertility following pregnancy termination.6,7 This discrepancy may be partly explained by two factors: the epidemiological studies were done on women from low-risk groups (women in stable relationships or of upper socioeconomic status); and if the infection is restricted to the cervix and endometrium, possibly reflecting lack of tubal involvement, long-term fertility may not be affected. We believe, however, that it is advisable for all women (or, if funds are limited, all single younger women) requesting termination of pregnancy to be screened for C trachomatis. When positive for this organism the woman should be counselled, given a 10-14 day course of tetracycline or erythromycin, and her sexual partner (or partners) referred for screening and treatment. Whether the remaining women should be given a short prophylactic course of antibiotics is open to debate. Department of Obstetrics and Gynaecology, Northern General Hospital, Sheffield S5 7AU
MICHAEL COHN PETER STEWART
Scheibel J. Significance of cervical Chlamydia trachomatis infection in postabortal pelvic inflammatory disease. Obstet Gynecol 1977; 60: 322-25. 2. Qvigstad E, Skaug K, Jerve F, Fylling P, Ulstrup JC. Pelvic inflammatory disease associated with Chlamydia trachomatis infection after therapeutic abortion. a prospective study. Br J Vener Dis 1983; 59: 189-92. 3. Osser S, Persson K. Postabortal pelvic infection associated with Chlamydia trachomatis and the influence of humoral immunity. Am J Obstet Gynecol 1984; 150: 699-703. 4. Møller BR, Ahrons S, Laurin J, Mårdh P-A. Pelvic infection after elective abortion associated with Chlamydia trachomatis. Obstet Gynecol 1982; 59: 210-13 5. Weström L. Effect of acute pelvic inflammatory disease on fertility. Am J Obstet Gynecol 1975; 121: 707-13. 6. Daling JR, Spadoni LR, Emanuel I. Role of induced abortion in secondary infertility. Obstet Gynecol 1981; 57: 59-61. 7. World Health Organisation Task Force on Sequelae of Abortion, Special Programme of Research, Development and Research Training in Human Reproduction. Secondary infertility following induced abortion. Stud Fam Plann 1984; 15: 291-95.
1. Westergaard L, Philipsen T,
MONITORING OF RHEUMATOID ARTHRITIS
SIR,-Professor Bull and colleagues’ (Oct 21, p 965) presume that there should be a single measure of disease activity in rheumatoid arthritis (RA). Such a measure would be helpful to clinicians, research workers, and auditors, but no single measure exists and it would be inappropriate to draw serious conclusions from this study.
Consensus analysis is of doubtful statistical validity and, along with small sample sizes, we should be cautious when using it as an argument against measurement of a variable. Since most measurements are continuous variables, methods to reduce the number of variables should be based on the Pearson correlation coefficient. Principal components analysis is a well established
technique used for rejection or selection of variables.’ Bull and colleagues’ investigation clustered a small homogeneous group of patients on a single suppressive therapy from this complex heterogeneous disease, and derived a single best test--erythrocyte sedimentation rate (ESR). Correlation of ESR to clinical measures of disease activity was poor; however, this finding should not be interpreted as showing clinical tests to be unhelpful. Statistically unrelated features should be identified to provide a simple disease model that still reflects its complexity. It is important to interpret correctly the information provided by each of the many measures in rheumatology. There is confusion in the terminology used to describe aspects of the disease process—eg, activity and severity. Some features of RA are potentially reversible-ie, synovitis and C-reactive protein (CRP)--and others reflect irreversible damage, such as radiological destruction and disability. Evidence suggests that reversible features (also termed process or activity measures) will predict irreversible damage (severity or outcome measures). Furthermore, analysis of an activity measure at one time-point is less meaningful than the measurement of an area under the curve over a period of time.’ ESR is a heterogeneous measure which may reflect widely different processes in early active and end-stage rheumatoid disease. In 33 non-erosive RA patients with early synovitis of hands and feet and an ESR of less than 30, we have shown that a complex of IgA and alpha-1-antitrypsin was the only variable from ten clinical and laboratory measures, including ESR, that predicted erosions.3 In contrast patients with established disease and raised acute-phase reactants will radiologically progress unless ESR and CRP are controlled.4 To concentrate on single measures is less rewarding than grading RA on more than one aspect of the disease process. A study of haemoglobin (Hb), platelets, albumin, globulins, alkaline phosphatase, ESR, CRP, painful joint count, pain score, grip strength, synovitis score, morning stiffness, and Ritchie index in 371 patients with RA over 6 months by principal components analysis demonstrated the advantage of an algorithm determining disease activity being used for staging disease. This activity index is based on ESR, CRP, synovitis score, morning stiffness, and Ritchie index. Analysis shows that ESR is a major contributor to the total variation in the data with high correlations of 0.70 (GRP), — 0-62 (Hb), - 0-60 albumin, 0-59 (platelets). However, it would be ill-judged to use this as evidence that ESR is the only variable that should be considered. Although the ESR/CRP correlation is high the linear regression to predict one from the other would have an R2 of about 0-5. Rather than recommend the use of a single inadequate "gold standard" for monitoring disease, investigators should activity indices based on more than one variable. If composite indices of rheumatoid activity were then combined to a validated severity index, such a grading of disease would enable critical assessment of patients in both the short and long term. evaluate
Staffordshire Rheumatology Centre, Haywood Hospital,
P. T. DAWES
Stoke-on-Trent ST6 7AG
M. J. DAVIS
Mathematics
Department, University of Keele,
P. JONES
Staffordshire
F. ZIADE
Jollife IT. Discarding variables in a principal component analysis. 1: artificial data. Appl Statistics 1972; 21: 160-73. 2. Borg G, Allander E, Lund B, et al. Auranofin improves outcome in early rheumatoid arthritis: results from a 2-year double blind, placebo controlled study J Rheumatol 1988; 15: 1747-54. 3. Davis MJ, Dawes PT, Fowler PD, et al. Development of erosions in RA: an association with the complex of immunoglobulin A-alpha 1-antitrypsin. Br J Rheumatol 1989; (suppl 1): 60. 4. Dawes PT, Fowler PD, Clarke S, Fisher J, Lawton A, Shadforth MF. Rheumatoid arthritis: treatment which controls the C-reactive protein and erythrocyte sedimentation rate reduces radiological progression. Br J Rheumatol 1986; 25: 1.
44-49.
MJ, Dawes PT, Fowler PD, et al. Comparison and evaluation inflammatory index for use in patients with RA. Br J Rheumatol (in press)
5. Davis
of
an
POST-ABORTION CHLAMYDIAL PELVIC INFECTION
SIR,-We agree with Mr Wood and Dr Muscat (Oct 14, p 928) that Chlamydia trachomatis is a frequent isolate from the cervices of women requesting termination of pregnancy. We have done endocervical swabs on 1874 consecutive outpatients seeking pregnancy termination between 1985 and 1988. C trachomatis was detected in 155 patients and Neisseriagonorrhoeae in 3, 1 of whom also harboured chlamydia. The overall infection rate for these two organisms was 8 33%. 71 % of women were single and in these the infection rate was 9-75%, significantly higher than that for married or previously married women (relative risk 240; 95% confidence intervals [CI] 136, 4-22). The rates for married, divorced, or separated women were 4-3%, 6-3%, and 5-7%, respectively. Single women under the age of 25 had the highest rate—10-2% (relative risk 1 -95,95% CI 1 -35,2-80). Nulliparous patients with a previous spontaneous or induced abortion had a lower rate of infection than primigravid patients (7-6% compared with 9-2%). Scandinavian studiesm3 have shown that the frequency of post-abortal endometritis or salpingitis was 20-28% where C trachomatis was isolated in the cervix before termination. In two of these investigations younger patients with endocervical chlamydia had an even greater risk of post-abortal infection. In the short term, post-abortal pelvic infection may mean extra patient time in hospital. Treatment of chlamydia-positive women reduces the frequency of post-abortal infection.’ The long-term sequelae are more uncertain. Despite Westrom’s reports that at least 12-8% of women are infertile after one episode of laparoscopically proven pelvic infection, epidemiological studies have not demonstrated an increased risk of secondary subfertility following pregnancy termination.6,7 This discrepancy may be partly explained by two factors: the epidemiological studies were done on women from low-risk groups (women in stable relationships or of upper socioeconomic status); and if the infection is restricted to the cervix and endometrium, possibly reflecting lack of tubal involvement, long-term fertility may not be affected. We believe, however, that it is advisable for all women (or, if funds are limited, all single younger women) requesting termination of pregnancy to be screened for C trachomatis. When positive for this organism the woman should be counselled, given a 10-14 day course of tetracycline or erythromycin, and her sexual partner (or partners) referred for screening and treatment. Whether the remaining women should be given a short prophylactic course of antibiotics is open to debate. Department of Obstetrics and Gynaecology, Northern General Hospital, Sheffield S5 7AU
MICHAEL COHN PETER STEWART
Scheibel J. Significance of cervical Chlamydia trachomatis infection in postabortal pelvic inflammatory disease. Obstet Gynecol 1977; 60: 322-25. 2. Qvigstad E, Skaug K, Jerve F, Fylling P, Ulstrup JC. Pelvic inflammatory disease associated with Chlamydia trachomatis infection after therapeutic abortion. a prospective study. Br J Vener Dis 1983; 59: 189-92. 3. Osser S, Persson K. Postabortal pelvic infection associated with Chlamydia trachomatis and the influence of humoral immunity. Am J Obstet Gynecol 1984; 150: 699-703. 4. Møller BR, Ahrons S, Laurin J, Mårdh P-A. Pelvic infection after elective abortion associated with Chlamydia trachomatis. Obstet Gynecol 1982; 59: 210-13 5. Weström L. Effect of acute pelvic inflammatory disease on fertility. Am J Obstet Gynecol 1975; 121: 707-13. 6. Daling JR, Spadoni LR, Emanuel I. Role of induced abortion in secondary infertility. Obstet Gynecol 1981; 57: 59-61. 7. World Health Organisation Task Force on Sequelae of Abortion, Special Programme of Research, Development and Research Training in Human Reproduction. Secondary infertility following induced abortion. Stud Fam Plann 1984; 15: 291-95.
1. Westergaard L, Philipsen T,
MONITORING OF RHEUMATOID ARTHRITIS
SIR,-Professor Bull and colleagues’ (Oct 21, p 965) presume that there should be a single measure of disease activity in rheumatoid arthritis (RA). Such a measure would be helpful to clinicians, research workers, and auditors, but no single measure exists and it would be inappropriate to draw serious conclusions from this study.
Consensus analysis is of doubtful statistical validity and, along with small sample sizes, we should be cautious when using it as an argument against measurement of a variable. Since most measurements are continuous variables, methods to reduce the number of variables should be based on the Pearson correlation coefficient. Principal components analysis is a well established
technique used for rejection or selection of variables.’ Bull and colleagues’ investigation clustered a small homogeneous group of patients on a single suppressive therapy from this complex heterogeneous disease, and derived a single best test--erythrocyte sedimentation rate (ESR). Correlation of ESR to clinical measures of disease activity was poor; however, this finding should not be interpreted as showing clinical tests to be unhelpful. Statistically unrelated features should be identified to provide a simple disease model that still reflects its complexity. It is important to interpret correctly the information provided by each of the many measures in rheumatology. There is confusion in the terminology used to describe aspects of the disease process—eg, activity and severity. Some features of RA are potentially reversible-ie, synovitis and C-reactive protein (CRP)--and others reflect irreversible damage, such as radiological destruction and disability. Evidence suggests that reversible features (also termed process or activity measures) will predict irreversible damage (severity or outcome measures). Furthermore, analysis of an activity measure at one time-point is less meaningful than the measurement of an area under the curve over a period of time.’ ESR is a heterogeneous measure which may reflect widely different processes in early active and end-stage rheumatoid disease. In 33 non-erosive RA patients with early synovitis of hands and feet and an ESR of less than 30, we have shown that a complex of IgA and alpha-1-antitrypsin was the only variable from ten clinical and laboratory measures, including ESR, that predicted erosions.3 In contrast patients with established disease and raised acute-phase reactants will radiologically progress unless ESR and CRP are controlled.4 To concentrate on single measures is less rewarding than grading RA on more than one aspect of the disease process. A study of haemoglobin (Hb), platelets, albumin, globulins, alkaline phosphatase, ESR, CRP, painful joint count, pain score, grip strength, synovitis score, morning stiffness, and Ritchie index in 371 patients with RA over 6 months by principal components analysis demonstrated the advantage of an algorithm determining disease activity being used for staging disease. This activity index is based on ESR, CRP, synovitis score, morning stiffness, and Ritchie index. Analysis shows that ESR is a major contributor to the total variation in the data with high correlations of 0.70 (GRP), — 0-62 (Hb), - 0-60 albumin, 0-59 (platelets). However, it would be ill-judged to use this as evidence that ESR is the only variable that should be considered. Although the ESR/CRP correlation is high the linear regression to predict one from the other would have an R2 of about 0-5. Rather than recommend the use of a single inadequate "gold standard" for monitoring disease, investigators should activity indices based on more than one variable. If composite indices of rheumatoid activity were then combined to a validated severity index, such a grading of disease would enable critical assessment of patients in both the short and long term. evaluate
Staffordshire Rheumatology Centre, Haywood Hospital,
P. T. DAWES
Stoke-on-Trent ST6 7AG
M. J. DAVIS
Mathematics
Department, University of Keele,
P. JONES
Staffordshire
F. ZIADE
Jollife IT. Discarding variables in a principal component analysis. 1: artificial data. Appl Statistics 1972; 21: 160-73. 2. Borg G, Allander E, Lund B, et al. Auranofin improves outcome in early rheumatoid arthritis: results from a 2-year double blind, placebo controlled study J Rheumatol 1988; 15: 1747-54. 3. Davis MJ, Dawes PT, Fowler PD, et al. Development of erosions in RA: an association with the complex of immunoglobulin A-alpha 1-antitrypsin. Br J Rheumatol 1989; (suppl 1): 60. 4. Dawes PT, Fowler PD, Clarke S, Fisher J, Lawton A, Shadforth MF. Rheumatoid arthritis: treatment which controls the C-reactive protein and erythrocyte sedimentation rate reduces radiological progression. Br J Rheumatol 1986; 25: 1.
44-49.
MJ, Dawes PT, Fowler PD, et al. Comparison and evaluation inflammatory index for use in patients with RA. Br J Rheumatol (in press)
5. Davis
of
an