{"id":1269,"date":"2016-04-06T20:54:05","date_gmt":"2016-04-06T19:54:05","guid":{"rendered":"https:\/\/blogs.bmj.com\/adc\/?p=1269"},"modified":"2016-03-19T21:04:30","modified_gmt":"2016-03-19T20:04:30","slug":"dethrone-the-landmark-trial","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/adc\/2016\/04\/06\/dethrone-the-landmark-trial\/","title":{"rendered":"Dethrone the “Landmark Trial”"},"content":{"rendered":"

\"Geo_Position-512\"There is a long honoured tradition in a number of specialities, and sub-specialities, of knowing The Landmark Trials. The studies that demonstrated that something works or that some method is better than another.<\/p>\n

But Landmark Trials are bunkum.<\/p>\n

<\/p>\n

There’s a couple of problems with Landmark Trials though; firstly –\u00a0the general rule is that the earliest trials in a subject show report much greater effects than later ones. This has been demonstrated in a fair few examples – including this classic from 1998 showing that the in\u00a0non-significant studies is greater than\u00a0delay tends to be in\u00a0significant ones:<\/p>\n

\"Picture1\"<\/a><\/p>\n

(doi:10.1001\/jama.279.4.281)<\/p>\n

In terms of effects and time, then this ‘cinnamon in diabetes’ review is fascinating – it’s arranges in chronological order of publication:<\/p>\n

\"graphic-7.large\"<\/a><\/p>\n

(doi: 10.1370\/afm.1517 – ignore that meta-analytic diamond by the way – it’s meaningless – the I-sq <\/a>is 84%)<\/span><\/p>\n

But perhaps the greatest example of why we should destroy the edifice of the Landmark Trial is this huge analysis by the genius of John P. A. Ioannidis<\/a>, who took about a decade’s worth of studies from major journals\u00a0that had been cited over 1000 times, and looked to see what the subsequent studies showed. His\u00a0conclusion was<\/p>\n

“Contradiction and initially stronger effects are not unusual in highly cited research of clinical interventions and their outcomes.”<\/em><\/p><\/blockquote>\n

Only 44% of these ‘Landmark’ studies ended up having subsequent studies confirming the size and direction of effect they had found.<\/p>\n

Of course, it’s interesting to know what led us to do what we do. But let’s not make the ‘Landmark Trial’ a\u00a0thing of clinical importance; systematic reviews are what should guide our practice.<\/a>\u00a0Landmark trials are just for the historian in us.<\/p>\n