Financial analysts, known for their penchant to wield prescribing data, may have jumped the gun recently.

Deutsche Bank analysts wrote in an investor note that new prescriptions for GlaxoSmithKline diabetes drug Avandia fell to about zero from 10% during the two days from May 22 to May 23. “Two days of data is not enough to reach sensible conclusions on the trend for Avandia new prescriptions,” GSK later told Bloomberg.

ImpactRx, which supplied the data on which the analysts based their May 23 note, added, “We believe insufficient time has elapsed…and it’s premature to conclude any dramatic or lasting changes in physician prescribing behavior at this point.” Either way, scripts have dropped since a May 21 article reported that Avandia users were 43% more likely to have a heart attack.

ImpactRx has done business with GSK and Deutsche Bank, but president and CEO Richard Altus said GSK had not pressured him to issue the caveat.

In early June, IMS Health released data showing Avandia NRx declined 16% in the first week after the journal article. GSK’s SVP for pharmaceuticals and vaccines was quoted as saying figures showed a 15% to 20% drop in Avandia prescriptions since the paper appeared.