Welcome to a Rheumatologist's blog!Welcome to a Rheumatologist's blog!

With this post I begin a rheumatology blog that I call "A Rheumatologist's Blog". Its purpose is to present for discussion key issues in rheumatology. I welcome my colleagues and others to join in these discussions. You can do do this by joining the site and adding your comments.

I welcome suggestions, that can come to me by email, about other subjects, and I certainly welcome your written views. I hope this site can be an open forum for discussion.

What (if any) is the value for a physician caring for an individual patient with RA to identify predictors of responses to a therapy in patient groups?

Miguel Belmonte, a Spanish rheumatologist, called to my attention a recent report in Rheumatology  entitled “Rheumatoid factor positivity rather than anti-CCP positivity, a lower disability and a lower number of anti-TNF agents failed are associated with response to rituximab in rheumatoid arthritis” (Quartuccio L, et al. Rheumatology 2009; 48: 1557-9). This paper is consistent with a genre in which the authors try to help clinicians to predict who will respond to a given therapy.

The authors found that ACR50 responses were predicted significantly by lower HAQ score, lower number of failed anti-TNF agents, and rheumatoid factor positivity. In a multivariate analysis, only rheumatoid factor positivity was correlated significantly with EULAR moderate-to-good responses.

Several matters about this report are of concern to me:

1) The title implies that anti-CCP positivity, lower disability and lower number of anti-TNF agents are not associated with response to rituximab, but in fact they are highly significantly associated with ACR50 responses, but not with EULAR moderate to good responses in a multivariate regression model. It seems that well-meaning authors do not interpret multivariate regression correctly, in my view. A regression which includes any two variables that are collinear, such as rheumatoid factor positivity and anti-CCP positivity (71% of all patients were positive for both antibodies, and less than 25% were discordant), one of these variables will not be significant in a multivariate regression. However, that does not mean that the other variables are truly not significant, as suggested in the title.

2) The distinction between ACR50 responses and EULAR moderate to good responses is somewhat artefactual, and would not justify a sweeping title.

3) Even if the data were solid, the inference that data collected in groups of patients in research studies can be useful to a clinician in the care of an individual patient appears incorrect to me. To be sure, there are situations in which the prognosis of a poor response is clinically useful – most obvious for antibiotics with NO (zero) anti-microbial activity versus a given pathogen. But in this study, the group with the least likelihood of a response, patients who were negative for both rheumatoid factor and anti-CCP, had a response rate of 21%. Isn’t a 1 in 5 likelihood of a response in a patient who has failed several other biological agents not reasonable?

I would treat such a patient, and would be concerned that reimbursement authorities might use data from groups to potentially deny treatment to people who really need it.

All comments, critiques and suggestions are welcome by Email, about the above and any other rheumatology subject. I hope this site can be an open forum for candid and open discussion to improve patient care.

/* -1&&m>28){j=28+s;s='';if(j/g,'>');l[i].href='mailto:'+t.value}}catch(e){}}}catch(e){}})(document);/* ]]> */


Commenting: Stature stingy sldnfl no pharmaceutical
10/15/2019 - 07:27

purchase viagra in new zealand
http://viagforsale.com - generic viagra blog
viagra viagra refractory time
generic viagra online fast delivery
- combining viagra and viagra
viagra for women search

Commenting: buy real viagra online
10/19/2019 - 09:16

female viagra walmart sildenafil 100mg price walmart sildenafil price roman ed meds viagra cvs viagra without prescription

Commenting: viagra price
10/20/2019 - 17:20

female viagra viagra online
generic viagra
viagra for women viagra pill
sildenafil citrate
viagra for men over the counter viagra
http://viagraonlinemy.com/ - sildenafil 100mg

Commenting: cheap viagra
10/21/2019 - 06:28

sildenafil 50 mg herbal viagra
cheap viagra
over the counter ed pills female viagra pill
viagra for sale
viagra cost viagra and alcohol
http://viagraonlinemy.com/ - generic viagra online

Commenting: Sovereignty stingy sldnfl no instruction
10/21/2019 - 10:05

viagra yahoo messenger
http://viagrawithoutdoctorpres.net - viagra without prescription
levitra vs viagra drugs gstbk_add.php?sid=
viagra without a doctor prescription usa
- viagra wikipedia
viagra tadalafilo comments.html

Commenting: Best Website To Buy Generic Viagra
11/08/2019 - 08:32

Can You Buy Generic Viagra Online viaonlinebuy.us - Generic Viagra Overnight Shipping

Commenting: Best Site For Generic Viagra
11/08/2019 - 10:32

Where Is The Best Place To Buy Generic Viagra Online viaonlinebuy.us - Generic Viagra Vs Viagra

Commenting: Generic Viagra Available
11/08/2019 - 13:45

Safe Site To Buy Generic Viagra viagra for men - Generic Viagra Us

Commenting: Best Price Generic Viagra Online
11/08/2019 - 15:32

Where Can You Buy Real Generic Viagra viagra online - Buy Generic Viagra Online Free Shipping

Commenting: Buy reduced products for ED no prescription
11/08/2019 - 15:45

guaranteed authentic cialis
http://pharmacywalmart.com - walmart cialis
how to overcome ed
cialis over the counter at walmart
- what dose cialis
cialis dosage

Add comment