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. 2013 Oct 26;10:11. doi: 10.1186/1742-7622-10-11

Table 1.

Recommended sample sizes and decision rules for numbers of clusters up to n min for the community health worker data quality assessment example

Number of clusters
    2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
ICC = 0.01
samples per cluster, k
13
7
5
4
5
3
4
3
2
2
3
2
2
2
2
2
2
2
1
 
total sample size, n
26
21
20
20
30
21
32
27
20
22
36
26
28
30
32
34
36
38
20
 
decision rule, d
4
3
3
3
4
3
5
4
3
3
5
4
4
4
5
5
5
5
3
 
α
0.093
0.081
0.096
0.095
0.040
0.077
0.073
0.069
0.092
0.062
0.036
0.081
0.056
0.038
0.071
0.050
0.035
0.024
0.091
 
β
0.048
0.091
0.079
0.078
0.065
0.087
0.022
0.045
0.076
0.096
0.034
0.040
0.050
0.062
0.021
0.027
0.033
0.041
0.075
 
Expected Costs, Scenario 1 †
$1,260
$1,710
$2,200
$2,700
$3,300
$3,710
$4,320
$4,770
$5,200
$5,720
$6,360
$6,760
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
 
Expected Costs, Scenario 2 ‡
$1,900
$1,950
$2,200
$2,500
$3,300
$3,150
$4,000
$4,050
$4,000
$4,400
$5,400
$5,200
$5,600
$6,000
$6,400
$6,800
$7,200
$7,600
$7,000
ICC = 0.025
samples per cluster, k
14
7
7
4
5
3
4
3
2
2
3
2
2
2
2
2
2
2
1
 
total sample size, n
28
21
28
20
30
21
32
27
20
22
36
26
28
30
32
34
36
38
20
 
decision rule, d
4
3
4
3
4
3
5
4
3
3
5
4
4
4
5
5
5
5
3
 
α
0.084
0.090
0.069
0.100
0.045
0.080
0.077
0.072
0.094
0.063
0.038
0.083
0.057
0.039
0.072
0.051
0.036
0.025
0.091
 
β
0.074
0.098
0.062
0.083
0.070
0.090
0.025
0.048
0.078
0.097
0.036
0.041
0.051
0.063
0.022
0.028
0.034
0.042
0.075
 
Expected Costs, Scenario 1
$1,280
$1,710
$2,280
$2,700
$3,300
$3,710
$4,320
$4,770
$5,200
$5,720
$6,360
$6,760
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
 
Expected Costs, Scenario 2
$2,000
$1,950
$2,600
$2,500
$3,300
$3,150
$4,000
$4,050
$4,000
$4,400
$5,400
$5,200
$5,600
$6,000
$6,400
$6,800
$7,200
$7,600
$7,000
ICC = 0.05
samples per cluster, k
18
10
7
6
5
3
4
3
2
2
3
2
2
2
2
2
2
2
1
 
total sample size, n
36
30
28
30
30
21
4
27
20
22
36
26
28
30
32
34
36
38
20
 
decision rule, d
5
4
4
4
4
3
5
4
3
3
5
4
4
4
5
5
5
5
20
 
α
0.093
0.071
0.082
0.056
0.052
0.085
0.085
0.076
0.097
0.065
0.041
0.086
0.060
0.041
0.075
0.053
0.038
0.026
0.091
 
β
0.083
0.095
0.073
0.082
0.078
0.094
0.029
0.052
0.080
0.100
0.040
0.043
0.054
0.065
0.023
0.029
0.036
0.044
0.075
 
Expected Costs, Scenario 1
$1,360
$1,800
$2,280
$2,800
$3,300
$3,710
$4,320
$4,770
$5,200
$5,720
$6,360
$6,760
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
 
Expected Costs, Scenario 2
$2,400
$2,400
$2,600
$3,000
$3,300
$3,150
$4,000
$4,050
$4,000
$4,400
$5,400
$5,200
$5,600
$6,000
$6,400
$6,800
$7,200
$7,600
$7,000
ICC = 0.1
samples per cluster, k
68‡‡
15
9
6
5
4
4
3
3
3
3
2
2
2
2
2
2
2
1
 
total sample size, n
136
45
36
30
30
28
32
27
30
33
36
26
28
30
32
34
36
38
20
 
decision rule, d
17
6
5
4
4
4
5
4
4
5
5
4
4
4
5
5
5
5
3
 
α
0.096
0.092
0.090
0.075
0.067
0.082
0.099
0.086
0.052
0.077
0.048
0.091
0.064
0.045
0.080
0.058
0.041
0.029
0.091
 
β
0.099
0.093
0.082
0.099
0.093
0.073
0.038
0.060
0.078
0.036
0.047
0.047
0.058
0.070
0.026
0.033
0.040
0.048
0.075
 
Expected Costs, Scenario 1
$2,360
$1,950
$2,360
$2,800
$3,300
$3,780
$4,320
$4,770
$5,300
$5,830
$6,360
$6,760
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
 
Expected Costs, Scenario 2
$7,400
$3,150
$3,000
$3,000
$3,300
$3,500
$4,000
$4,050
$4,500
$4,950
$5,400
$5,200
$5,600
$6,000
$6,400
$6,800
$7,200
$7,600
$7,000
ICC = 0.15
samples per cluster, k
††
45‡‡
13
9
6
4
5
3
3
3
3
2
2
2
2
2
2
2
1
 
total sample size, n
 
135
52
45
36
28
40
27
30
33
36
26
28
30
32
34
36
38
20
 
decision rule, d
 
17
7
6
5
4
6
4
4
5
5
4
28
4
5
5
5
5
3
 
α
 
0.099
0.100
0.082
0.087
0.095
0.090
0.096
0.060
0.086
0.055
0.096
0.069
0.049
0.085
0.062
0.045
0.032
0.091
 
β
 
0.099
0.090
0.087
0.080
0.083
0.043
0.067
0.086
0.042
0.053
0.051
0.062
0.074
0.029
0.036
0.043
0.051
0.075
 
Expected Costs, Scenario 1
 
$2,850
$2,520
$2,950
$3,360
$3,780
$4,400
$4,770
$5,300
5830.000
$6,360
$6,760
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
 
Expected Costs, Scenario 2
 
$7,650
$3,800
$3,750
$3,600
$3,500
$4,400
$4,050
$4,500
4950.000
$5,400
$5,200
$5,600
$6,000
$6,400
$6,800
$7,200
$7,600
$7,000
ICC = 0.2
samples per cluster, k
††
††
40
12
9
6
6
4
3
3
3
3
2
2
2
2
2
2
1
 
total sample size, n
 
 
160
60
54
42
48
36
30
33
36
39
28
30
32
34
36
38
20
 
decision rule, d
 
 
20
8
7
6
7
5
4
5
5
5
4
4
5
5
5
5
3
 
α
 
 
0.096
0.099
0.077
0.098
0.091
0.077
0.068
0.095
0.063
0.041
0.073
0.052
0.090
0.066
0.048
0.035
0.091
 
β
 
 
0.100
0.090
0.091
0.067
0.050
0.071
0.093
0.047
0.060
0.074
0.066
0.078
0.032
0.039
0.047
0.055
0.075
 
Expected Costs, Scenario 1
 
 
$3,600
$3,100
$3,540
$3,920
$4,480
$4,860
$5,300
$5,830
$6,360
$6,890
$7,280
$7,800
$8,320
$8,840
$9,360
$9,880
$10,200
  Expected Costs, Scenario 2     $9,200 $4,500 $4,500 $4,200 $4,480 $4,500 $4,500 $4,950 $5,400 $5,850 $5,600 $6,000 $6,400 $6,800 $7,200 $7,600 $7,000

This table assumes pu = 0.25, pl = 0.05, αmax= βmas = 0.1.

† Assuming costs of $500 per cluster and $10 per individual sampled. ‡ Assuming costs of $300 per cluster and $50 per individual sampled. †† Too few clusters to determine a system. ‡‡ May not be applicable to CHW problem, as recommended sample size exceeds average number of households per cluster.