Van den Broek 2006.
Clinical features and settings |
Presenting signs and symptoms: New episode of suspected malaria, which could include fever, history or other complaints indicating possible malaria infection Previous treatment for malaria: Excluded if malaria confirmed (treated or untreated) within the previous four weeks Clinical setting: Malaria outpatient centre Country: Colombia Malaria endemicity: Hypoendemic, annual parasite rate 2% to 5% Malaria endemic species:P. vivax (54%), P. falciparum (46%) |
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Participants |
Sample size: 896 Age: All ages eligible. Actual numbers of children and adults not stated, although the report mentions that many workers were included. Sex: Both males and females eligible. Most of the participants were male (646, 79%) Co‐morbidities and pregnancy: No exclusion criteria based on co‐morbidities. No details of the frequency of these conditions in the participant population is presented. Parasite density of microscopy positive cases: Geometric mean approximately 2300 parasites per μl for both P. falciparum and P. vivax |
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Study design | Enrollment was prospective. The sampling method was not described. Three RDTs were tested. All individuals received all three tests. | |
Target condition and reference standard(s) |
Target condition: Malaria parasitaemia Reference standard: Microscopy thick and thin blood smears Person(s) performing microscopy: Well trained, experienced microscopists Microscopy setting: Not stated Number of high power fields examined before declaring negative: At least 200 Number of observer or repeats: One, except for about one third of the slides (especially low density parasitaemias and mixed infections). In this case, another microscopist viewed the slide and discordant results between microscopists or between slides and RDTs were sent to the University of Antioquia for external cross‐checking. Resolution of discrepancies between observers: Disagreements between the internal and external results were sent to a third laboratory: the National Health Institute in Bogota. In cases where both external laboratories disagreed with the internal laboratory, results were corrected accordingly. |
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Index and comparator tests |
Commerical name of RDT: Paracheck Pf (Orchid Biomedical Systems, Goa, India) OptiMAL‐IT (Diamed AG, Switzerland) NOW Malaria ICT (Binax, Portland, USA) Parasite(s) designed to detect: Paracheck Pf ‐ P. falciparum OptiMAL‐IT ‐ P. falciparum or mixed infection, non‐falciparum species only NOW Malaria ICT ‐ P. falciparum or mixed infection, non‐falciparum species only Designated Type: Paracheck Pf ‐ Type 1 OptiMAL ‐ IT ‐ Type 4 Now Malaria ICT ‐ Type 2 Batch numbers: Not stated Transport and storage conditions: Not described Person(s) performing RDT: A bacteriologist. Where the result was ambiguous, two bacteriologists read the test results. RDT setting: At the malaria centre |
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Follow‐up | Not applicable | |
Notes | Source of funding: Medicins Sans Frontieres and its donors. The American Society of Tropical Medicine and Hygiene assisted with publication expenses. | |
Table of Methodological Quality | ||
Item | Authors' judgement | Description |
Representative spectrum? All tests | Unclear | All participants were patients presenting with suspected malaria, but the sampling method was not described |
Acceptable reference standard? All tests | No | Microscopists viewed at least 200 high power fields before declaring a slide negative; however the findings were only verified by a second independent reader for a third of slides |
Partial verification avoided? All tests | Yes | All participants who received the index test also received the reference test |
Differential verification avoided? All tests | Yes | The same reference test was used regardless of the index test results |
Incorporation avoided? All tests | Yes | The index test does not form part of the reference standard |
Reference standard results blinded? All tests | Yes | Report states that microscopists were blinded to the results of RDTs |
Index test results blinded? All tests | Yes | Report states that RDTs were blinded to the results of microscopy |
Uninterpretable results reported? All tests | Yes | There were no uninterpretable results; and weak lines were scored as positive |
Withdrawals explained? All tests | Unclear | The number of participants originally enrolled in the study was not explicitly stated; therefore it was not possible to assess whether there were any withdrawals |