Advanced Certification Heart Failure (ACHF)

Initial Patient Population

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HF Sample Size Requirements

Hospitals that choose to sample have the option of sampling quarterly or sampling monthly. A hospital may choose to use a larger sample size than is required. Hospitals whose Initial Patient Population size is less than the minimum number of cases per quarter for the measure set cannot sample. Hospitals that have five or fewer HF discharges (both Medicare and non-Medicare combined) in a quarter are not required to submit HF patient level data to the QIO Clinical Warehouse¹ and Joint Commission’s Data Warehouse.

Regardless of the option used, hospital samples must be monitored to ensure that sampling procedures consistently produce statistically valid and useful data. Due to exclusions, hospitals selecting sample cases MUST submit AT LEAST the minimum required sample size.

The following sample size tables for each option automatically build in the number of cases needed to obtain the required sample sizes. For information concerning how to perform sampling, refer to the Population and Sampling Specifications section in this manual.

Quarterly Sampling

Hospitals performing quarterly sampling for HF must ensure that its Initial Patient Population and sample size meet the following conditions:

Quarterly Sample Size
Based on Initial Patient Population Size for the HF Measure Set

Hospital's Measure

Average Quarterly Initial Patient Population Size “N”	Minimum Required Sample Size “n”
≥ 1516	304
381 -– 1515	20% of Initial Patient Population size
76 –- 380	76
6 –- 75	No sampling; 100% Initial Patient Population required
0 - 5	Submission of patient level data is encouraged but not required: CMS: if submission occurs, 1-5 cases of Initial Patient Population may be submitted 1 The Joint Commission: if submission occurs, 100% Initial Patient Population required

Monthly Sampling

Hospitals performing monthly sampling for HF must ensure that its Initial Patient Population and sample size meet the following conditions:

Monthly Sample Size
Based on Initial Patient Population Size for the HF Measure Set

Hospital's Measure

Average Monthly Initial Patient Population Size “N”	Minimum Required Sample Size “n”
≥ 506	102
131 -– 505	20% of Initial Patient Population size
26 -– 130	26
<26	No sampling; 100% Initial Patient Population required

Sample Size Examples

• Quarterly sampling:
  • The HF Initial Patient Population size for a hospital has been 500 patients per quarter during the past year. The required quarterly sample size would be 100 (twenty percent of 500) heart failure patients per quarter -- as this number is smaller than the maximum condition (i.e., 304 cases) and larger than the minimum condition (i.e., 76 cases).
  • A hospital’s HF Initial Patient Population size is 1,482 patients during the third quarter. The required sample size is 20% of the patient population or 297 cases for the quarter (twenty percent of 1,482 equals 296.4 rounded to the next highest whole number equals 297).
  • A hospital’s HF Initial Patient Population size is 5 patients during the first quarter. Submission of patient level data is not required. If the hospital chooses to submit patient level data:
    • CMS: the quarterly sample size would be 1 – 5 cases for the quarter.¹
    • The Joint Commission: the required quarterly sample size would be 100% of the patient population or 5 cases for the quarter.

• Monthly sampling:
  • A hospital’s HF Initial Patient Population size is 25 patients during March. Since this is less than the minimum condition (i.e., 26 cases), no sampling is allowed or 100% of the patient population of 25 cases is required.
  • A hospital’s HF Initial Patient Population size is 503 patients during July. The required sample size is 20% of the patient population or 101 cases for the month (twenty percent of 503 equals 100.6 rounded to the next highest whole number equals 101).

¹ The Heart Failure (HF) core measure sampling methodology is applicable to the ACHF measures. Data collection for the ACHF measures is required by Joint Commission Disease-Specific Care Certification.