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Archive for April, 2011

Weaving case reports into Ishikawa diagrams

26 Apr, 11 | by Dr Dean Jenkins

Ishikawa diagrams are named after Professor Kaoru Ishikawa of Tokyo University, a highly regarded Japanese expert in quality management.

“He first used it in 1943 to help explain to a group of engineers at Kawasaki Steel Works how a complex set of factors could be related to help understand a problem. [Cause and Effect] CE Diagrams have since become a standard tool of analysis in Japan and in the West in conjunction with other analytical and problem-solving tools and techniques.
CE Diagrams are also often called Ishikawa Diagrams, after their inventor, or Fishbone Diagrams because the diagram itself can look like the skeleton of a fish.” HCi Professional Services, Australia.

Kam Cheong Wong has described the use of such diagrams to assist learning about cause and effect in medicine (1). He concludes that:

“Rare but critical cases should be studied and included in an Ishikawa diagram to remind clinicians of relevant information during their clinical reasoning processes.”

… and cites an example case (2) from BMJ Case Reports that provides an example for a diagram about secondary amenorrhoea.

I think these types of diagrams are very helpful as are concept maps in general. The Ishikawa diagrams are particularly interesting since they are so focussed on cause and effect and, as Dr Wong argues, enable the linking of concepts in case reports to other forms of documented causes and effects.

1. Wong KC. Using an Ishikawa diagram as a tool to assist memory and retrieval of relevant medical cases from the medical literature. Journal of Medical Case Reports. 2011;5(1):120. Available at: Accessed April 21, 2011.

2. Bhansali A, Shanmugasundar G, Walia R, Santosh R, Dutta P. Acute abdomen and hypothyroidism. Case Reports. 2009;2009(jun08 1):bcr1220081356-bcr1220081356. Available at: Accessed April 26, 2011.

PatientsLikeMe study refutes Lithium use in motorneurone disease

25 Apr, 11 | by Dr Dean Jenkins

Case Reports usually involve just the one patient. When patients get together and join a social network their shared experiences could be used to evaluate research questions that would otherwise go unexplored or take time to answer. This is exactly what the website PatientsLikeMe claim to have done with the use of Lithium Carbonate in the treatment of Amyotrophic Lateral Sclerosis – a type of motorneurone disease – and they have published the work in Nature Biotechnology (1).

“To reduce potential bias owing to lack of randomization, we developed an algorithm to match 149 treated patients to multiple controls (447 total) based on the progression of their disease course. At 12 months after treatment, we found no effect of lithium on disease progression. Although observational studies using unblinded data are not a substitute for double-blind randomized control trials, this study reached the same conclusion as subsequent randomized trials, suggesting that data reported by patients over the internet may be useful for accelerating clinical discovery and evaluating the effectiveness of drugs already in use.”

The sample of patients from a particular social media website will, by definition, be self-selected. Perhaps such groups would be better at generating qualitative rather than quantitative information. However, this approach could be used to evaluate off-label uses of drugs.

It is an interesting technique but care should be taken in interpreting such observations and it would be good to see other examples of this type of study and more analysis of the case-control selection algorithm. Small effects may be missed without careful elimination of bias.

1. Wicks P, Vaughan TE, Massagli MP, Heywood J. Accelerated clinical discovery using self-reported patient data collected online and a patient-matching algorithm. Nat Biotech. 2011;advance online publication. Available at: Accessed April 25, 2011.

‘Quality and Safety in Medicine’ Series: Atypical mycobacteria in a superficial femoral artery occlusion

20 Apr, 11 | by Emma

A rare cause of superficial femoral artery occlusion is discovered in a patient who undergoes surgery for worsening claudication. The patient is young and an occasional smoker. The authors go on to research the pathophysiology of the lesion and suggest how it might have been formed.

Seema Biswas

Atypical mycobacteria in a superficial femoral artery occlusion

‘Quality and Safety in Medicine’ Series: When a groin lump is more than a simple groin lump

13 Apr, 11 | by Emma

In this case of the series we highlight attention to detail.

The authors report a young footballer who presents acutely with an irreducible, painful groin lump. An incarcerated inguinal hernia is a reasonable diagnosis in spite of a combination of intriguing examination findings. The groin is explored and there is no hernia. Instead, a blood clot is found. The wound is not closed after evacuation of the clot; the authors continue to explore until the cause is revealed and treated effectively.

Seema Biswas

When a groin lump is more than a simple groin lump

‘Quality and Safety in Medicine’ Series: Faulty fetal packing

6 Apr, 11 | by Emma

Here the authors report the birth of a baby delivered by emergency caesarian section after preterm prolonged rupture of membranes. The situation must have been tense; and, there is considerable blood loss at surgery. The baby requires extensive resuscitation and transfusion. A depression is then noted in the baby’s skull. What now?

Seema Biswas

Faulty fetal packing

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