Critical appraisal of apparently evidence-based written advertising in Pakistan

Objectives The objective of the study was to critically assess references cited in support of claims in drug advertisements. Methods Drug advertising brochures were collected from privately practicing General Practitioners from different parts of Karachi. Three blinded reviewers then categorized each reference in the brochure according to the sources viz: journals (both Medline indexed and non-indexed), medical reference books, web addresses, personal communications or testimonials, abstracts presented at symposia/conferences, WHO and National Health Guidelines, ‘data on file’ and ‘others’ (which included a diverse set of references). Each reviewer then assessed and analyzed the references further into 2 broad categories: traceable and non-traceable. Traceable references were appraised and, depending upon the claim with which the reference was attached, were classified into justifiable, inaccurate/false, exaggerated and ambiguous. Results We collected a total of 175 different brochures. Thirty-nine (22.3%) brochures did not cite any references and were not subjected to further analysis. The remaining 136 (77.7%) contained a total of 559 references. 305 (54.6%) of these references were from Medline-indexed journals; 67 (12.0%) were from non-indexed journals; 55 (9.8%) references quoted medical reference books; 27 (4.8%) references cited web addresses; 12 (2.1%) references were personal communications/testimonials; 11 (2.0%) references referred to abstracts presented at symposia/conferences; 12 (2.1%) references were from WHO and National Health Guidelines; 8 (1.4%) references were listed as ‘data on file’, while the remainder that could not be defined were classified as ‘others’ (13.1%). Out of a total of 559 references, 249 (44.5%) could not be traced. After critically analyzing the 310 traceable references, 197 (63.5%) were adjudged justifiable, 30 (9.7%) inaccurate/false, 79 (25.5%) exaggerated and 15 (4.8%) ambiguous. Conclusion Results of this study show for the first time that the claims substantiated with references in the pharmaceutical advertisements in Pakistan are highly unreliable.