Appendix C_2022 NSCH Table of State Sample Sizes

Appendix C

2022 National Survey of Children’s Health
Table of State Sample Sizes

Appendix C
2022 NSCH - Estimated State Sample Sizes

Base Sample
Oversampling
Rate 1
'k'
State Sample Sizes
Alabama
4.0
Alaska
4.0
Arizona
4.0
Arkansas
4.0
California
3.0
Colorado
3.0
Connecticut
4.0
Delaware
4.0
District of Columbia
6.0
Florida
4.0
Georgia
3.0
Hawaii
2.0
Idaho
4.0
Illinois
4.0
Indiana
4.0
Iowa
6.0
Kansas
4.0
Kentucky
4.0
Louisiana
3.0
Maine
6.0
Maryland
4.0
Massachusetts
4.0
Michigan
4.0
Minnesota
4.0
Mississippi
4.0
Missouri
4.0
Montana
5.0
Nebraska
5.0
Nevada
3.0
New Hampshire
4.0
New Jersey
3.0
New Mexico
4.0
New York
3.0
North Carolina
4.0
North Dakota
5.0
Ohio
4.0
Oklahoma
4.0
Oregon
4.0
Pennsylvania
4.0
Rhode Island
4.0
South Carolina
4.0
South Dakota
5.0
Tennessee
4.0
Texas
3.0
Utah
3.0
Vermont
8.0
Virginia
3.0
Washington
4.0
West Virginia
5.0
Wisconsin
4.0
Wyoming
4.0
Total
Proportion by Strata

Proportion of
Households with
Children from
2020 ACS
'P'
29%
25%
34%
28%
43%
37%
37%
30%
17%
30%
35%
30%
38%
34%
34%
25%
36%
31%
32%
25%
39%
36%
36%
37%
25%
33%
21%
28%
34%
33%
41%
23%
34%
34%
23%
37%
28%
33%
36%
31%
32%
25%
35%
38%
44%
19%
41%
37%
22%
35%
27%

Base
Sample
Sampling
Variance1
‘R’
1.01
1.02
1.05
1.00
1.02
0.98
1.05
0.98
0.99
1.04
0.99
0.99
1.06
1.04
1.03
1.03
1.05
1.03
1.00
1.03
1.05
1.03
1.02
0.99
0.99
1.02
0.99
0.98
0.98
0.98
1.00
1.00
0.98
1.04
0.99
1.04
1.02
1.02
1.01
1.01
1.03
0.99
1.06
1.01
1.01
1.02
0.98
1.05
1.01
1.01
0.98

Total
Sample 2
5,900
6,800
5,400
6,500
34,500
9,700
4,000
5,300
5,300
5,600
9,300
7,500
4,000
4,400
4,400
4,400
4,300
5,300
7,200
5,000
4,200
3,600
4,500
3,500
7,300
4,400
5,100
5,500
6,100
4,300
4,400
7,600
35,000
5,200
4,800
8,700
6,200
13,000
8,300
5,300
5,200
4,800
13,000
6,600
3,700
4,000
4,400
3,900
6,300
3,800
10,000
357,500

Stratum 1
Stratum 2a
Sample
Sample
(Admin Flag
(Admin Flag
for HHLD
for HHLD w/o
w/Children)
Children)
4,100
1,700
4,000
2,800
4,000
1,500
4,500
2,000
23,500
11,000
6,300
3,500
3,000
1,000
3,800
1,500
3,400
2,000
4,100
1,500
6,000
3,200
2,500
5,000
3,000
900
3,200
1,200
3,200
1,200
3,200
1,200
3,200
1,100
3,600
1,700
4,700
2,500
3,600
1,400
3,300
900
2,600
1,000
3,400
1,000
2,600
900
4,700
2,600
3,300
1,200
3,100
2,000
3,800
1,600
3,900
2,200
3,100
1,200
3,000
1,300
4,500
3,100
20,500
14,500
3,800
1,500
3,100
1,600
6,400
2,300
4,100
2,100
8,700
4,300
5,900
2,400
3,600
1,700
3,800
1,400
3,200
1,500
9,000
3,800
4,500
2,100
2,700
1,000
2,800
1,300
3,100
1,300
2,900
1,000
3,900
2,400
2,800
1,000
6,200
3,900
239,500
118,000
67%
33%

These are the Stratum 1 oversampling rates and the sampling variances for the base production sample only. California, Colorado,
Georgia, Nebraska, New York, Ohio, Oregon, Pennsylvania, Tennessee, and Wyoming all have additional sample that may have
different oversampling rates and sampling variances.
2 Sample sizes include both the base production sample as well as the additional nationwide oversample of young children and state
oversamples in CA, CO, GA, NE, NY, OH, OR, PA, TN, and WY. All sample sizes have been rounded.
1

Appendix C
Calculations for Base Production State Sample Sizes
The oversampling rate (k) was calculated to maximize the sample from Stratum 1 without increasing the
variance (R) too much beyond that of a proportional stratified design of a similar cost.
(P) is the proportion of households with children based on the 2020 ACS audit 3.
The portion of the sample coming from each stratum was calculated using the oversampling rate (k) and
the proportion of all households in each of the sampling strata (W1 and W2a). Address valid rates, child
prevalence rates, and Screener and Topical returns rates were estimated by state and stratum primarily
using previous years’ response outcomes. A national total sample size of approximately 357,500 was
determined based on budget. This includes the base production sample for all states as well as a national
oversample aimed at getting additional interviews from children aged zero to five and additional sample
in California, Colorado, Georgia, Nebraska, New York, Ohio, Oregon, Pennsylvania, Tennessee, and
Wyoming. We expect the base production sample will produce approximately 700 Topical interviews per
state. The expected number of interviews along with previous years’ response information was used to
calculate stratum sample sizes (n1 and n2a) in each state.
For example, in Alabama 4:
The oversampling rate (k) was recalculated to be 4.0, for an R = 1.01. Of the 2020 ACS households
eligible for NSCH sampling, 21.1% would be put in Stratum 1 (W1) and 52.7% would be put in Stratum
2a (W2a).
The portion of the sample coming from Stratum 1 was estimated to be (k*W1) / (W2a + k*W1) = 61.6%
and the portion of the sample from Stratum 2a was 38.4%.
We can expect a completed Topical from 92.6% (Valid) * 38.0% (Screener) * 80.4% (Children) * 82.2%
(Topical) = 23.2% of addresses in Stratum 1 and 77.8% (Valid) * 45.7% (Screener) * 12.3% (Children) *
81.3% (Topical) = 3.6% of addresses in Stratum 2a.
Since we expect to get 700 Topicals per state, we can get the state sample size (n) by evaluating the
following:
(n * Portion of the sample from Stratum 1 * Stratum 1 completed Topical rate) + (n * Portion of the
sample from Stratum 2a * Stratum 2a completed Topical rate) = 700.
Within rounding, it then follows that n = 700 / (61.6% * 23.2% + 38.4% * 3.6%) = 4500. Now n1 = 4500
* 61.6% = 2800 and n2a = 4500 * 38.4% = 1700. These are the base production sample sizes in each stratum
for Alabama. 5

3

Before mailout, this will be updated with the 2021 ACS.
Note that numbers have been rounded here for all calculations.
5
These numbers do not match what is in the table since this shows only the calculation for Alabama’s base production
sample while the sample sizes in the table include the additional nationwide oversample of young children.
4