TABLE 3 Primary Outcome and Power ofthe Six IPTi-SP Trials

Location, Country

Ifakara, Tanzania

Navrongo, Ghana

Manhiça, Mozambique

Kumasi, Ghana

Lambaréné, Gabon

Tamale, Ghana

Reference

Schellenberg et al.

Chandramohan et al.

Macete et al.

Kobbe et al.

Grobusch et al.

Mockenhaupt et al.

 

Lancet 2001, 2005

BMJ 2005

JID 2006

CID 2007

JID 2007

AAC 2007

Primary outcome-protocol

Incidence of clinical malaria and severe anaemia episodes in each group by 12 months of age. The word “incidence” is not defined in the protocol

N/A

Incidence of first or only malaria episodes [sic] in each studycohort by 12 months of age

Rate of episodes of malaria and/or severe anaemia

Proportion of children between 3and 18 months of age with at least one episode of (1)anemia (Hb < 9g/dL) and (2) malaria (parasitemia with fever)

Incidence of clinical malaria, severe malaria, and hospital visits

Primary outcome-manuscript

First or only episode of clinical malaria and severe anaemia in the period from recruitmentto 1year of age

Incidence of all episodes of malaria associated fevers…and the incidence of anaemia during the intermittent treatment phase (2–15 months) and after the effect of the intervention had ceased (16–23 months)

Same as protocol

Not clear whether the primary outcome was “first or single malaria episodes” or “cumulative episodes” or malaria

(1) The proportion of children with at least 1 episode of mild anemia and (2) the proportion of children with at least 1 episode of malaria between 3 and 18 months of age. Anemia was defined as Hb<8.0g/dL. Malaria was parasitemia with fever.

Incidences of all and of first or only episodes of malaria and severe anemia during the intervention period

Assumptions – protocol

Control group: 0.63 incidence clinical malaria/PYAR; 0.42 incidence severe malaria/PYAR; 30% reduction in SP

N/A

Placebo incidence rate = 0.33 case/yr

Assumptions not presented

Placebo proportions—anemia: 0.28; malaria: 0.60

Assumptions not presented

Assumptions-manuscript

Control group: 0.36 clinical malaria/PYAR; 0.28 episodes of severe malaria/PYAR

Incidence in placebo group 25%

Same as protocol

Assumptions not presented

Same as protocol for anemia; no mention of malaria

Assumptions not presented

Power-protocol

Protocol says “adequate”

N/A

80% power to detect a protective efficacy of 30% against having at least one episode of malaria

Power not in protocol. Method of analysis not clearly defined

80% to detect a protective efficacy of 30% against having at least one episode of anemiaand 16% for malaria

No power calculation

Power-manuscript

80%

95% power to detect a 25% reduction (cluster randomization)

Same as protocol

Study designed with 80% power to detect 20% reduction in “hazards of developing malaria in the SP group, compared with the placebo group”

Same as protocol for anemia; no mention of malaria

Sample size adequate to detect 25% reduction in malaria and severe anemia

NOTES: N/A = not available to the committee; PYAR = person years at risk.

SOURCE: Compiled from the trial protocols provided by the IPTi Consortium and the published manuscripts of the studies.



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