Twists in the tale of impossible means

British Medical Journal, May 13, 2000 by Jon Havard Loge, Simon Wessely, Anthony Pelosi, Richard Savage

In which a copy of the original manuscript is found safe in Norway ...

EDITOR--Recently, Bland correctly identified impossible means for fatigue and scores with the general health questionnaire in a paper published by Pawlikowska et al in 1994.[1 2] The authors admitted the mistake and reported the correct values, but they could not explain how the values came to be incorrect in their paper.[3] Missing proofs, the theft of a computer, and the passage of time might seem like poor excuses and indicate unreliable researchers.

I can, however, confirm that the values reported by Chalder and Wessely in their authors' reply correspond with the values in the original manuscript. I received a copy in 1993, when the manuscript was being reviewed by the BMJ. On the front page one of the authors has written by hand: "submitted to the BMJ, not for citation." Since then my copy of the manuscript has been stored on a bookshelf at the University of Oslo. I checked it with some excitement after reading Bland's criticism to find that the values in the authors' reply were the same as those in my copy of the original manuscript (available on request).

Perhaps the authors were correct when they said that the manuscript had been attacked by gremlins. The gremlins seem to have attacked somewhere in the production line because the referees at the BMJ reviewed a manuscript with correct means.

Jon Havard Loge postdoctoral research fellow Department of Behavioural Sciences in Medicine, POB 1111 Blindern, 0317 Oslo, Norway j.h.loge@medisin.uio.no

[1] Bland M. Fatigue and psychological distress. BMJ 2000; 320:515. (19 February.)

[2] Pawlikowska T, Chalder T, Hirsch SR, Wallace P, Wright DJM, Wessely SC. Population based study of fatigue and psychological distress. BMJ 1994;308:763-6.

[3] Chalder T, Wessely S. Fatigue and psychological distress. BMJ 2000;320:515. (19 February.)

... the researchers rejoice that the gremlins were at the BMJ after all ...

EDITOR--Initially this correspondence was both painful and embarrassing to us,[1 2] but it has now become less so. It clearly shows, however, that there is no doubt that the analyses and conclusions of our paper written all those years ago remain valid and are certainly not faulty.

In March I received from Dr Loge a copy of the original manuscript that we sent him as a professional courtesy after we had submitted the manuscript to the BMJ. As he states in his letter above, the means are indeed correct. Hence our somewhat ungallant suggestion that the BMJ was attacked by gremlins though not gallant is accurate.

What have we learnt?

Firstly, we congratulate Bland for rereading an old paper and spotting what no one else had seen.

Secondly, we thank God for Norwegian colleagues who keep copies of old manuscripts.

Thirdly, we will not dispose of proof copies when the reprints finally arrive.

Fourthly, we feel sure that our sleepless nights over this one will be cured by receipt of a bottle of wine from the BMJ.

Simon Wessely professor of epidemiological and liaison psychiatry Academic Department of Psychological Medicine, Guy's, King's and St Thomas's School of Medicine and Institute of Psychiatry, London SE5 8AF s.wessely@iop.kcl.ac.uk

[1] Bland M. Fatigue and psychological distress. BMJ 2000; 320:515. (19 February.)

[2] Chalder T, Wessely S. Fatigue and psychological distress. BMJ 2000;320:515. (19 February.)

... the reviewer shows that the gremlins might have attacked on several fronts ...

EDITOR--Bland found that the analysis was flawed in a paper on fatigue and psychological distress that had been published by the BMJ in 1994.[1 2] He quite properly asks why nobody noticed this at the refereeing stage. The authors are unable to account for their errors and have tried, as they say, "totally ungallantly" to transfer the blame to the BMJ.[3] They also wonder how the referee could have failed to detect the mistakes.

I refereed the manuscript for that paper. I think I can explain the most serious discrepancy identified by Bland. The authors originally coded the four possible responses in each item of their main questionnaires as 1 to 4. Therefore total scores for the general health questionnaire ranged from 12 to 48 and those for the fatigue questionnaire from 11 to 44. I told them they had to code the responses as 0 to 3. It looks as if they gave the correct scores when describing the total sample but did not recode the responses when examining males and females separately. I made various other suggestions, but I was not going to rewrite the results section of the paper and I certainly draw the line at proof reading.

I remember this manuscript well for several reasons. At first I could make neither head nor tail of some of the analyses. I ended up being angry with myself for spending too much time--on a sunny Sunday afternoon--trying to understand the results instead of just recommending rejection. My irritation melted away when I got a note back thanking me for an "excellent" referee's report. At Christmas I received my first ever invitation to the BMJ's friends of the journal party, and I have always believed it was because of the high standard of that report.