Forms of rice

Description of rice

Rough rice (paddy rice)

Rice kernels still enclosed in an inedible, protective hull

Brown rice

Rice with only the hull removed. Bran layers and rice germ remain, giving the rice a brown colour

Parboiled rice

Rice pressurised to gelatinise the starch within the rice kernel, resulting in a firmer, more separate grain that is more stable and less susceptible to overcooking than regular‐milled white rice

Regular‐milled white rice (milled rice)

Polished whole rice, or polished rice. Hull, bran layer and germ have all been removed

Precooked rice

Regular milled white rice, parboiled milled white rice, and brown rice can be precooked and dehydrated before packaging. Examples of precooked rice are quick‐cooking rice, instant rice, and boil‐in‐the‐bag rice

Individually quick frozen (IQF) rice

Cooked grains are individually frozen before packaging

Crisped/puffed/expanded rice

Kernels can be processed in a number of different ways and shapes to meet particular manufacturing need

Study and year

(Country)

Participants

Type of rice fortification and dosage

Duration of intervention

Overall risk of bias

RCTs (individual randomisation)

Angeles‐Agdeppa 2008

(Philippines)

180 anaemic children aged 6‐9 years excluding severe anaemia (Hb < 70 g/L), history of blood disorders and other haemoglobinopathies

1. Participants were allocated to 3 groups of 60 each; receiving 160 g of cooked iron‐enriched rice with ferrous sulphate powder (ExFeSO₄), micronized ferric pyrophosphate (ExFeP80); and cooked unfortified rice

2. Interventions were given as 2‐week cycle with standard dishes during lunch, daily for 5 days/week as a supervised regimen.

6 months

High

Hardinsyah 2016

(Indonesia)

200 post‐menarchal adolescent girls 14‐18 years of age attending boarding school

1. Participants were randomly assigned to 2 groups: group 1 (n = 100) received meals containing fortified rice (iron, vitamin A, zinc, folic acid, thiamin, vitamin B₁₂); group 2 (n = 100) received meals prepared with unfortified rice.

2. All participants received the meals from the school kitchen.

3. Every meal given to students always contained rice, side dish and vegetable soup (once a day); side dishes being rotated between egg, fish, chicken, tempe, or tofu.

4 months

High

Hotz 2008

(Mexico)

180 non‐pregnant, non‐lactating women 18‐49 years of age with moderate to low Hb concentrations from 6 factories

1. Participants were allocated to 2 groups of 90 each. Group 1 received iron‐formula UltraRice® and group 2 received unfortified rice.

2. The iron fortificant was microencapsulated, micronized ferric pyrophosphate. The fortified rice was formulated to provide 20 mg of iron per daily portion. The fortified grains were mixed directly with dry, locally obtained rice.

3. For first 3 months of the study, the fortified grains were added at 2:100 (weight/weight), and each daily portion of rice consisted of 75 g of dry rice

4. For second half of the feeding period the blend rate was doubled to 4:100 and the daily quantity of dry rice was halved to 37 g per person, making the iron fortificant per daily portion same

6 months

High

Hussain 2014

(India)

222 iron‐ and vitamin A‐depleted children 5‐8 years of age attending a subsidised lunch feeding programme

1. Participants were randomly assigned to 1 of 6 groups: the group receiving fortified rice (n = 185) were randomly assigned to 5 subgroups based on the iron deficiency, iron‐deficiency anaemia and vitamin A deficient status at baseline.

2. The subgroups that were divided from the fortified rice were: group 1 (n = 37) : children receiving iron‐fortified meals; group 2 (n = 37) : children receiving beta‐carotene‐fortified meals; group 3 (n = 37): children receiving retinyl palmitate‐fortified meals; group 4 (n = 37): children receiving iron + retinyl palmitate‐fortified meals; group 5 (n = 37): children receiving iron + beta‐carotene‐fortified meals.

3. The meals were consumed under direct supervision, and the daily leftovers were weighed.

4. All the children were dewormed at baseline.

6 months

High

Losso 2017

(USA)

17 menstruating women with iron‐deficiency anaemia

1. Participants were randomly assigned to 1 of 2 groups: group 1 (n = 9) received 100 g of rice (0.75 cups of cooked rice in 2 servings) per day in a 1:1 ratio of fortified rice containing 18 mg elemental iron/100 g rice); group 2 (n = 6) received unfortified rice (0.5 mg iron/100 g rice).

2. The intervention lasted 2 weeks. The rice dishes were prepared in the Pennington metabolic kitchen and dispensed frozen in an insulated chest to the participants weekly in lots of 14 with instructions to heat and consume 1 rice dish twice a day.

2 weeks

High

Moretti 2006b

(India)

184 iron‐depleted children aged 6‐13 years from a primary school serving the Rock‐Colony neighbourhood

1. Participants were allocated to 2 groups of 92 children each: group 1 received rice‐based lunch meal fortified with 20 mg elemental iron (as micronized ground ferric pyrophosphate); group 2 received an identical but unfortified control meal.

2. Lunch was served 6 days/week (except for school holidays).

3. 3 local recipes of rice cooked with different seasoning ingredients were presented in repeating sequence.

4. At baseline and at the midpoint of the study, all participants were dewormed with 400 mg albendazole and were treated with vitamin A supplements (200000 IU) 4 months before the start of the study and study midpoint.

7 months

Low

Pinkaew 2013

(Thailand)

The study was conducted in 8 primary schools with children aged 4‐12 years and they were mainly from low‐income families.

1. School children with low serum zinc (n = 203) were randomised to 2 groups and group 1 received triple‐fortified rice (n = 101); group 2 received natural control rice (n = 102) as a component of school lunch meals.

2. The fortification level of the extruded rice grains was 10 mg iron, 9 mg zinc and 1050 mg vitamin A/g of extruded rice.

5 months

High

Pinkaew 2014

(Thailand)

One primary school in the Muang district, of Thailand with children aged 8‐12 years, were the study participants

1. Schoolchildren with general good health and no major chronic diseases aged 8‐12 years (n = 50) were recruited for the study.

2. Children who had consumed the triple‐fortified rice in a previous study or showed clinical symptoms of vitamin A deficiency (Bitot's spot or ocular signs of xerophthalmia) or serum retinol values of < 0.7mmol/L were excluded.

2 months

High

Radhika 2011

(India)

140 children aged between 5 and 11 years (with haemoglobin > 70 g/L)

1. Study participants were allocated to 2 groups of 70 children each. Group 1 received the fortified rice and group 2 received unfortified rice. Micronized ferric pyrophosphate was used to fortify the extruded rice kernels considering in vitro availability, and loss of iron during cooking consisting of 125 g rice (dry weight) with 19 mg iron (fortified rice); normal rice mixed with UltraRice® (extruded kernels containing MFPP of 3.14 µm mean particle size) in comparison with unfortified rice.

8 months

Low

Thankachan 2012

(India)

Total of 258 anaemic (Hb concentrations 115 g/L for 6–11 years and 120 g/L for 12 years) children attending 4 primary schools aged 6‐12 years

1. The children were assigned to 3 intervention groups of 86 children each to receive rice‐based lunch meals fortified with multiple micronutrients with either low‐iron (6.25 mg) or high‐iron (12.5 mg) concentrations or identical meals with unfortified rice.

2. The fortified, artificially extruded‐rice kernels contained 6.25 mg iron/g as micronized ground ferric pyrophosphate and were mixed with local natural rice at a 1:99 ratio to obtain low‐iron fortified rice.

3. To obtain high‐iron fortified rice, fortified artificially extruded rice, together with low‐iron fortified rice (prepared earlier) (6.25 mg iron/100 g raw rice) were mixed with natural rice at a 1:1:98 ratio to result in a fortification level of 12.5 mg iron/100 g natural raw rice.

4. The 3 types of rice (high iron: 12.5 mg iron/100 g, low iron: 6.5 mg iron/100 g, and control; 100 g raw rice/meal) were used to prepare lunch meals daily in the kitchen.

6 months

High

RCTs (cluster randomisation)

Parker 2015 (C)

(Burundi)

The study included 1071 children from 12 schools in Burundi aged between 7 and 11 years

1. 12 schools in Burundi were assigned to 2 groups. 1 group received UltraRice® (fortified rice) and the other group received traditional rice. UltraRice® (UR) premix kernels were manufactured to contain 100% of the recommended nutrient intakes (RNI) for iron, zinc, thiamin, and folic acid, through the school feeding programme.

2. Hb status was measured.

3. Children attending the intervention group schools received fortified rice with iron (17.8 mg), zinc (8.5 mg), thiamine (1.8 mg), and folic acid (600 mg) for 5 days/week for 7 months and children in control group schools received an equivalent unfortified rice containing endogenous quantities of iron (1.2 mg), zinc (1.7 mg), thiamin (0.1 mg), and folate (14 mg).

7 months

High

Perignon 2016 (C)

(Cambodia)

The study was a double‐blind cluster‐randomised, placebo‐controlled trial conducted among a total of 2440 school‐going children aged 6‐16 years.

1. 20 primary schools in Cambodia were randomised to 5 arms (4 intervention + 1 control arm). The 4 intervention groups were fortified cold‐extruded rice (UltraRice® original formulation), fortified hot‐extruded rice (UltraRice® new formulation), fortified hot‐extruded rice Nutririce, non‐fortified rice (placebo) and a control group without the school feeding programme.

2. The control schools were randomly selected from 16 primary schools participating in another programme of WFP (take‐home ration programme) not receiving a school meal.

3. The UltraRice® original (URO) was produced by cold extrusion and the UltraRice new (URN) and NutriRice® by hot extrusion. Fortification process was carried out in such a way that every 100 g of URO provided 10.76 mg iron, 3.04 mg zinc; 170 folic acid, 1.06 vitamin B1, URN 7.55 mg iron, 2.02 mg zinc, 2140 IU vitamin A, 280 folic acid, 1.43 vitamin B1 and NutriRice® 7.46 mg iron, 3.68 mg zinc, 960 IU vitamin A, 140 folic acid and 0.69 vitamin B1

6 months

High

Non‐randomised studies (controlled before‐and‐after studies)

Ara 2019

(Bangladesh)

870 women aged 15‐49 years excluding severe anaemia (435/group) at baseline and 800 (400/group) at end line

1. Rice flour was fortified using hot extrusion technology and homogeneous blending of the same with unfortified rice.

2. The intervention group received 30 kg fortified rice; the control group received 30 kg non‐fortified rice for every month from January 2013‐December 2013.

3. After 12 months of fortified rice/non‐fortified rice consumption, the end line data were collected from December 2016‐April 2017.

4. Follow‐up of the World Food Programme interventions was done on another group from the same area.

12 months

High

Della Lucia 2016

(Brazil)

131 non‐anaemic children between 2 and 6 years old, of both genders, participated in the study.

1. Participants from the selected preschools received either micronutrient fortified rice (UltraRice®) or unfortified polished rice, as part of school meals, 50 g daily, Monday through Friday.

4 months

High

Gershoff 1977

(Thailand)

2250 children aged 1.5‐9 years from 29 villages

1. The villages were divided into 5 groups: group 1 no intervention provided; group 2 placebo control, unfortified rice plus day­care centre food for preschool children; group 3, received fortified rice containing 0.087 3% thiamin naphthalene disulfonate, 0.0815% of retinol acetate, and 0.8% FeP04:4H20 (0.2% iron) plus day‐care centre food; group 4 received fortified rice containing 0.087 3% thiamin naphthalene disulfonate, 0.0815% of retinol acetate, 0.8% FeP04:4H20 plus 20% L‐lysine HCI and I 0% L‐threonine in addition to day‐care centre food; group 5 received fortified rice containing 0.087 3% thiamin naphthalene disulfonate, 0.0815% of retinol acetate, 0.8% FeP04:4H20 plus 20% L‐lysine HCI and I 0% L‐threonine, no day‐care centre food

2. Before being mixed with the other ingredients. the rice was cooked by putting it in water and cooking under low heat for 15 minutes.

4 years

High

Nogueira Arcanjo 2013

(Brazil)

303 children 2‐5 years of age attending 2 public schools in City of Sobral‐Ceará, in the northeast of Brazil, between August and December 2010

1. Participants from 2 schools received the assigned intervention to the schools: children in group 1 (school A) (n = 138) received iron‐fortified rice (UltraRice®); children in group 2 (school B) (n = 165) received unfortified standard rice.

2. The study rice was consumed with poultry, which was the customarily consumed meal for Tuesdays at the schools.

18 weeks

High

Non‐randomised studies (controlled cross‐sectional study)

Salcedo 1950

(Philippines)

574 children aged between 3 and 18 years

2188 Government employees with their families

1416 military personnel (clinical assessment limited to 350 in the experimental group and 116 in the control group)

1. Study participants were given 200‐250 g of fortified or unfortified rice. Both groups consumed between 200‐250 g of rice.

2. Among military personnel, a total of 1300 were given fortified rice, but clinical assessment was limited to 350 participants serving as the experimental group and an additional 116 participants serving as the control.

3. Fortification consisted of rice grains impregnated with premix and mixed at 1:200 to have a final fortified rice (per kg) with 4.4 mg thiamine, 33 mg niacin, 28.6 mg elemental (as iron pyrophosphate).

8 months

High

CBA: controlled before‐and‐after study; Hb: haemoglobin; RCT: randomised controlled trial

Study

Place

 Race/ethnicity

 Occupation

 Gender

Religion/

culture/education

Socio‐economic status

Social status

Others/ disability/

age/

sexual orientation

Overall PROGRESS‐Plus

Angeles‐Agdeppa 2008

Metro Manila, Division Pasig; Philippines

No specific mention, apart from the locality of the school in the capital city

School children

Male 99 + female 81

No religion mentioned; children going to San Joaquin Elementary School (public)

Not mentioned

Not mentioned

Anaemic children; sexual orientation not mentioned

This study was carried out among 180 anaemic children going to a government elementary school.

Ara 2019

Vulnerable Group
Development (VDG) beneficiaries in 5 districts of Bangladesh

Not mentioned specifically, however, they were the local resident women.

It included professional workers,
unskilled workers,
agricultural labourers,
home servants and
housewives. Most of the study population were housewives

Non‐pregnant women aged 15‐49 years

No religion mentioned; nearly 25% without any education

No direct estimate provided; however, most of the study participants were from lower socioeconomic strata

Not mentioned

Women with severe anaemia were excluded. Sexual orientation is not mentioned

The study was carried out among 870 women of reproductive age and local residents of Bangladesh

Della Lucia 2016

Brazil

Not specified

School‐going children

No religion mentioned, attending philanthropic schools

Not mentioned

Not mentioned

Children, 2‐6 years old

This study was carried out in 2 public schools among non‐anaemic children 2‐6 years of age during 4 consecutive months.

Gershoff 1977

Chiang Mai villages in tile valley of the Ping River, Thailand

Thai children

Children in the community

Male 1121

+ female 1109

No religion mentioned. Children in the study villages

Not mentioned

Low/middle

Normal children; sexual orientation not mentioned

The study included 2230 children attending pre‐school and school from the low/middle social background

Hardinsyah 2016

Medan of North Sumatra Province, Indonesia

The majority of participants' ethnicity was Javanese and Bataknese

Teenage girls attending boarding school

Female

There is mention of the Ramadan fasting month during the second week of June

The family income ranges from 4.9 million to 5.5 million Rupiahs (Approximately 340 to 390 US Dollars)

Not mentioned

Age 14‐18 years of age

This study was carried out among post‐menarchal adolescent girls attending boarding school in Indonesia. The study lasted 4 months.

Hotz 2008

Morelos State, Mexico

Mexican women

Factory workers

Women only

No religion mentioned; 18‐49 years

Low/middle school

Low/middle

Anaemic women; sexual orientation not mentioned

This study included women with altitude‐adjusted Hb concentrations between 105
and 135 g/L from low/middle social background, non‐pregnant and non‐lactating.

Hussain 2014

India

Iron and vitamin A‐depleted 5‐8‐year‐old children attending a subsidised lunch feeding programme

Children attending a school‐based feeding programme

Not specified

Not reported

Not reported

Not mentioned, although programme is subsidised

5‐8 years of age

This study included 222 children aged 5‐8 years attending a school where there was a subsidised lunch feeding programme in India receiving a 200‐250 g meal of cooked rice daily.

Losso 2017

Baton Rouge, USA

In the iron‐fortified group: 4 white, 3 black or African‐American, 1 Asian, 1 other; in the unfortified rice group: 3 white, 2 black or African American, 1 Asian

Women only

Not reported

Not mentioned

Not mentioned

18‐50 years of age

This study included women with iron‐deficiency anaemia recruited through web and phone interviews and then in a clinic.

Moretti 2006b

Franciscan primary school serving the
population of Rock‐Colony neighbourhood, in crowded urban
slum of Bangaoore; India

Indian

School‐going children

Not mentioned

6‐13 years

Low

Low

Children with iron deficiency; sexual orientation not mentioned

Study included children having iron deficiency from an urban slum neighbourhood in India, belonging to low socioeconomic status and low social class

Nogueira Arcanjo 2013

Public schools in City of Sobral‐Ceará, in the northeast of Brazil

Not reported

School‐going children

Fortified rice group: 65 male: 73 female; unfortified rice group: 79 male: 86 female

2‐5 years of age

Not reported. Family income 300 USD or less (it is unclear if this is weekly or monthly income ‐ not reported).

126/138 participants from iron‐fortified group versus 154/165 participants from unfortified group.

Not mentioned

Children 2‐5 years of age. Other information not reported

This before‐and‐after study included children 2‐5 years of age from 2 public schools in northeast Brazil receiving the school lunch programme and the fortified/unfortified intervention once a week.

Parker 2015 (C)

The study was carried out in Muyinga Province in Burundi catering to mainly agrarian population

Burundians

School‐going children

Female: 51.1% in intervention arm, 55.3% in control arm

Religion was not mentioned. 7‐11 years

Mean socioeconomic status score quintile = 3.03 (1.45) for intervention arm and 2.97 (1.37) for control arm

Not mentioned

Children with Hb level 70‐110 g/L and those who had not taken any nutritional supplements during the past 1 month since commencement of the study were included. Sexual orientation is not mentioned.

This cluster‐RCT included 904 children who were mild to moderately anaemic from the selected schools of Burundi and mainly with an agricultural background.

Perignon 2016 (C)

The study was carried out in Kampung Speu Province of Cambodia

Cambodians

School‐going children

Male and female participants had equal representation

(50% each)

6‐16 years

Not mentioned

Not mentioned

Excluding severely anaemic children. All in the eligible age group were included in the study. Sexual orientation not mentioned

The cluster‐RCT included children from selected schools of Cambodia in KamPong Speu province with rice farming as a predominant occupation and income source.

Pinkaew 2013

Satun province, west coast of southern Thailand

Thai Muslims

School children

Male, 98 + female 105

Majority Muslim, age group of 7‐12 years

Low

Low/middle

Children with zinc deficiency; sexual orientation not mentioned

This study included school‐going children from low socioeconomic status and having zinc deficiency in Thailand.

Pinkaew 2014

Muang District, Satun Province of southern Thailand

Thai Muslims

School Children

Males, 24 and females, 26

Majority Muslims in the age group 8‐12 years

Low

Low/middle

Children who had consumed the triple‐fortified rice before or showed clinical symptoms of VAD (Bitots spot or ocular signs of xerophthalmia) or serum retinol values of < 0.7m

mol/L were
excluded

This study included school‐going children from low socioeconomic status and having zinc deficiency in Thailand.

Radhika 2011

Village of Keesara; Andhra Pradesh State in India

Indian

School children

Male 56 + female 90

No mention of religion; age group of 5‐11 years

Low/middle

Low/middle

Anaemic children; sexual orientation not mentioned

The study included anaemic children from low‐middle socioeconomic background belonging to a rural area in India.

Salcedo 1950

Bataan, Philippines

Filipinos

Children and military personnel

Male and female, but proportions not reported

No mention of religion or education

Children lived in a welfare institution; military personnel were fully employed

Not mentioned

No exclusions were reported; sexual orientation was not mentioned

The study was conducted among children living in a welfare institution and among military personnel in the Philippines.

Thankachan 2012

Primary schools in
Bangalore Urban District of Karnataka State; South India

Indians

School children

Male 47%, female 53%

Hindu > Christians > Muslim; 6‐12 years

Low/middle school

Low

Anaemic children; sexual orientation not mentioned

This study included anaemic school going children from low socioeconomic background from an urban area India.

Hb: haemoglobin; RCT: randomised controlled trial

Study

Elemental iron

(mg)

Vitamin A^a

(mg)

Zinc

(mg)

Folic acid

(µg)

Vitamin B₁ (thiamin)

(mg)

Vitamin B₂ (riboflavin)

(mg)

Vitamin B₃ (niacin)

(mg)

Vitamin B₆ (pyridoxine)

(mg)

Vitamin B₁₂ (cobalamin)

(µg)

Angeles‐Agdeppa 2008

6.25

‐

‐

‐

‐

‐

‐

‐

‐

Ara 2019 (CBA)

6

0.15

4.00

130

0.40

1.0

Della Lucia 2016 (CBA)

8.4

‐

4.20

144

0.72

‐

‐

‐

‐

Gershoff 1977 (CBA)

0.2

0.81

0.087

0.04

0.2

0.81

0.087

0.04

0.2

0.81

0.087

0.04

Hardinsyah 2016

10.8

0.28

5.20

145

‐

3.2

Hotz 2008

26.6

‐

‐

‐

‐

‐

‐

‐

‐

Hussain 2014

4

‐

‐

‐

‐

‐

‐

‐

‐

1.20 (as beta‐carotene)

‐

‐

‐

‐

‐

‐

‐

‐

0.18

‐

‐

‐

‐

‐

‐

‐

4

0.18

‐

‐

‐

‐

‐

‐

‐

4

1.20 (as beta‐carotene)

‐

‐

‐

‐

‐

‐

‐

Losso 2017

18

‐

‐

‐

‐

‐

‐

‐

‐

Moretti 2006b

20

‐

‐

‐

‐

‐

‐

‐

‐

Nogueira Arcanjo 2013 (CBA)

112.8

‐

‐

‐

‐

‐

‐

‐

‐

Parker 2015 (C)

11.9

‐

5.70

400

1.80

‐

‐

‐

‐

Perignon 2016 (C)

10.67

‐

3.04

170

1.06

‐

‐

‐

‐

7.55

0.64

2.02

280

1.43

‐

12.57

‐

3.8

7.46

0.29

3.68

140

0.69

‐

7.98

0.92

1.26

Pinkaew 2013

20

2.10

18

‐

‐

‐

‐

‐

‐

Pinkaew 2014

20

2.10

18

‐

‐

‐

‐

‐

‐

Radhika 2011

15

‐

‐

‐

‐

‐

‐

‐

‐

Salcedo 1950 (CBA)

2.86

‐

‐

‐

0.44

‐

0.33

‐

‐

Thankachan 2012

12.5

0.50

3

75

0.38

‐

5

0.38

0.75

6.25

0.50

3

75

0.38

‐

5

0.38

0.75

C: cluster randomised; CBA: controlled before‐and‐after study

Study

Haemoglobin threshold (g/L)

Criteria

Angeles‐Agdeppa 2008

Anaemia was defined as haemoglobin concentration in blood < 120 g/L

Not mentioned

Ara 2019

< 120 g/L in non‐pregnant and non‐lactating women

Not mentioned

Della Lucia 2016

≥ 110 g/L was used as a cut off for including children in the study. Anaemia was not defined

Not reported

Gershoff 1977

Haemoglobin levels were categorised as deficient < 100, low 100‐90 (g/L)

Not mentioned

Hardinsyah 2016

Severe anaemia: < 80 g/L; moderate anaemia: 80‐109 g/L; mild anaemia: 110‐119 g/L; non anaemia: ≥ 120 g/L

WHO (WHO 2011a)

Hotz 2008

< 122 g/L, adjusted for average altitude of the study sites (1100 m) with the use of an equation

CDC (CDC 1989)

Hussain 2014

< 110 g/L and severely anaemic (Hb < 75 g/L) were excluded

Not mentioned

Losso 2017

Not reported (iron‐deficiency anaemia was defined based on iron and ferritin levels in serum)

Not reported

Moretti 2006b

< 115 g/L in children aged 5–11 years

WHO (WHO 2001)

Nogueira Arcanjo 2013

< 110 g/L in children < 5 years of age

WHO (WHO 2001)

Parker 2015 (C)

For school‐aged children at 1500 m above sea level, mild anaemia was defined as Hb 115‐119 g/L, moderate anaemia Hb 85‐114 g/L, and severe anaemia Hb < 85 g/L

WHO (WHO 2011f)

Perignon 2016 (C)

< 115 g/L for children aged 6‐11 years, < 120 g/L for children aged 12‐14 years and girls aged ≥ 15 years and < 130 g/L for boys aged ≥ 15 years

WHO (WHO 2001)

Pinkaew 2013

< 120 g/L

Not mentioned

Pinkaew 2014

Not reported

Not reported

Radhika 2011

In children aged 5–11 years, anaemia (mild to moderate) was defined as Hb 70‐115 g/L.

WHO (WHO 2001)

Salcedo 1950

Not reported

Not reported

Thankachan 2012

< 115 g/L in children aged 6–11 years and < 120 g/L in participants aged ≥ 12 years

Not mentioned

CDC: Centers for Disease Control and Prevention; Hb: haemoglobin; WHO: World Health Organization

Outcome (all studies included in the analysis)

Study (ICC)

RR (95% CI)

Tau²

Chi²

P value

I²

Anaemia

(Angeles‐Agdeppa 2008; Hardinsyah 2016; Hotz 2008; Parker 2015 (C); Perignon 2016 (C); Radhika 2011; Thankachan 2012)

Parker 2015 (C) (0)

0.83 (0.64 to 1.08)

0.06

16.06

0.01

63%

Parker 2015 (C) (0.001)

0.83 (0.64 to 1.08)

0.06

15.72

0.02

62%

Parker 2015 (C) (0.002)

0.83 (0.64 to 1.08)

0.06

15.71

0.02

62%

Parker 2015 (C) (0.005)

0.83 (0.64 to 1.07)

0.06

15.12

0.02

60%

Parker 2015 (C) (0.01)

0.83 (0.64 to 1.08)

0.06

14.80

0.02

59%

Parker 2015 (C) (0.02723)

0.83 (0.64 to 1.07)

0.05

13.08

0.04

54%

Parker 2015 (C) (0.1)

0.81 (0.64 to 1.03)

0.04

10.03

0.12

40%

Perignon 2016 (C) (0)

0.83 (0.67 to 1.03)

0.04

13.17

0.04

54%

Perignon 2016 (C) (0.001)

0.83 (0.67 to 1.04)

0.04

13.15

0.04

54%

Perignon 2016 (C) (0.002)

0.83 (0.66 to 1.04)

0.04

13.16

0.04

54%

Perignon 2016 (C) (0.005)

0.83 (0.66 to 1.05)

0.04

13.12

0.04

54%

Perignon 2016 (C) (0.01)

0.83 (0.65 to 1.05)

0.05

13.12

0.04

54%

Perignon 2016 (C) (0.02723)

0.83 (0.64 to 1.07)

0.05

13.08

0.04

54%

Perignon 2016 (C)( 0.1)

0.83 (0.63 to 1.09)

0.06

13.08

0.04

54%

Outcome (all studies included in the analysis)

Study (ICC)

MD (95% CI)

Tau²

Chi²

P value

I²

Haemoglobin concentration (Angeles‐Agdeppa 2008; Hardinsyah 2016; Hotz 2008; Hussain 2014; Losso 2017; Moretti 2006b; Parker 2015 (C); Perignon 2016 (C); Pinkaew 2013; Radhika 2011; Thankachan 2012)

Parker 2015 (C) (0)

1.69 (0.48 to 2.91)

1.82

24.15

0.007

59%

Parker 2015 (C) (0.001)

1.70 (0.48 to 2.92)

1.81

23.90

0.008

58%

Parker 2015 (C) (0.002)

1.71 (0.49 to 2.93)

1.81

23.69

0.008

58%

Parker 2015 (C) (0.005)

1.73 (0.51 to 2.96)

1.80

23.18

0.01

57%

Parker 2015 (C) (0.01)

1.77 (0.54 to 3.00)

1.79

22.62

0.01

56%

Parker 2015 (C)) (0.02723)

1.85 (0.61 to 3.10)

1.77

21.73

0.02

54%

Parker 2015 (C)) (0.1)

1.98 (0.71 to 3.25)

1.76

20.96

0.02

52%

Perignon 2016 (C)) (0)

1.85 (0.61 to 3.09)

1.77

21.98

0.02

55%

Perignon 2016 (C)) (0.001)

1.85 (0.61 to 3.09)

1.77

21.97

0.02

54%

Perignon 2016 (C)) (0.002)

1.85 (0.61 to 3.09)

1.77

21.96

0.02

54%

Perignon 2016 (C)) (0.005)

1.85 (0.61 to 3.10)

1.77

21.93

0.02

54%

Perignon 2016 (C)) (0.01)

1.85 (0.61 to 3.10)

1.77

21.89

0.02

54%

Perignon 2016 (C)) (0.02723)

1.85 (0.61 to 3.10)

1.77

21.73

0.02

54%

Perignon 2016 (C)) (0.1)

1.86 (0.61 to 3.11)

1.78

21.15

0.02

53%

C: cluster‐randomised trial; CI: confidence interval; ICC: intra‐cluster correlation coefficient; MD: mean difference; RR: risk ratio