Malaria rapid diagnostic kits: quality of packaging, design and labelling of boxes and components and readability and accuracy of information inserts

Abstract

Background: The present study assessed malaria RDT kits for adequate and correct packaging, design and labelling of boxes and components. Information inserts were studied for readability and accuracy of information.

Methods: Criteria for packaging, design, labelling and information were compiled from Directive 98/79 of the European Community (EC), relevant World Health Organization (WHO) documents and studies on end-users' performance of RDTs. Typography and readability level (Flesch-Kincaid grade level) were assessed.

Results: Forty-two RDT kits from 22 manufacturers were assessed, 35 of which had evidence of good manufacturing practice according to available information (i.e. CE-label affixed or inclusion in the WHO list of ISO13485:2003 certified manufacturers). Shortcomings in devices were (i) insufficient place for writing sample identification (n=40) and (ii) ambiguous labelling of the reading window (n=6). Buffer vial labels were lacking essential information (n=24) or were of poor quality (n=16). Information inserts had elevated readability levels (median Flesch Kincaid grade 8.9, range 7.1-12.9) and user-unfriendly typography (median font size 8, range 5-10). Inadequacies included (i) no referral to biosafety (n=18), (ii) critical differences between depicted and real devices (n=8), (iii) figures with unrealistic colours (n=4), (iv) incomplete information about RDT line interpretations (n=31) and no data on test characteristics (n=8). Other problems included (i) kit names that referred to Plasmodium vivax although targeting a pan-species Plasmodium antigen (n=4), (ii) not stating the identity of the pan-species antigen (n=2) and (iii) slight but numerous differences in names displayed on boxes, device packages and information inserts. Three CE labelled RDT kits produced outside the EC had no authorized representative affixed and the shape and relative dimensions of the CE symbol affixed did not comply with the Directive 98/79/EC. Overall, RDTs with evidence of GMP scored better compared to those without but inadequacies were observed in both groups.

Conclusion: Overall, malaria RDTs showed shortcomings in quality of construction, design and labelling of boxes, device packages, devices and buffers. Information inserts were difficult to read and lacked relevant information.

Figure 1

Four-band RDT. The allocated place for writing sample identification is too small. The grid at the left hand may be confused with a sample well. There are two different reading labels at each side of the reading window, of which the lower one is printed on a label that is not well fixed.

Figure 2

Example of RDT cassettes. Most of the cassettes have separated wells for sample and buffer application. There is no uniform labelling of the wells: different characters (e.g. "S", "A") are used randomly for the sample well, buffer well and combined sample/buffer well. The reading labels are indicated with acronyms, characters or numbers.

Figure 3

Interpretation section of the information insert and cassette of a Plasmodium falciparum/Plasmodium vivax RDT. The real device has a single sample/buffer whereas the depicted one displays separate wells. The characters used for the reading label on the illustration are inverted compared to the real device.

Figure 4

Interpretation section of the information insert and cassette of a P. falciparum/P. vivax RDT. Shape and labels of wells and reading window are different between the real and the depicted device. Characters are embedded in the plastic housing and poorly discernable. The text is correct and complete (even the prozone effect and how to deal with it) but less readable (Flesch-Kincaid grade level 9.1).

Figure 5

Information insert of a three-band RDT, procedure section. There is a discrepancy between the reading time mentioned in the text compared to that showed on the illustration.

Figure 6

Typographic features of RDT information inserts (n = 40): font sizes and line spacing.

Figure 7

Example of typography used in RDT information inserts: the package insert on the top is user-unfriendly (font size 6, line spacing 0,5, close letter type, average number of words per line 21, Flesch-Kincaid grade 9,5). The package insert on the background, from the same company but for another RDT uses a better typography (font size 8, line spacing 2, open letter type, average number of words per line 14), but the readability is still elevated (Flesch-Kincaid grade 9,8).

Figure 8

Readability of the RDT information inserts (n = 40) and job aids (n = 7) expressed as Flesch-Kincaid grade level.

Figure 9

Interpretation section of the information insert of a three-band P. falciparum/pan-species RDT. For invalid tests, only the absence of all lines is mentioned, not the possibility of a visible test line without a control line. The invalid results are not depicted. The print quality is poor, no colours are used for the control and test lines.

Figure 10

Illustration depicting sampling of capillary blood. The health care worker's hand is depicted without gloves. The simultaneous presence of English and French text may be difficult for a non-experienced reader.

Figure 11

CE-label displayed on a RDT kit box. The shape and relative dimensions of the characters do not comply with the requirements as mentioned in the EC Directive 98/79 (depicted in the insert, upper right corner). There is no authorized representative (EC-REP) affixed, although required.

Figure 12

Example of the lateral side of a RDT box: all essential information is printed on a single side of the box, contributing to clear storage.