Primary ovarian insufficiency quality of life scale

Assignment 3 Rubric & Answers – Sahyoun Question Answers Possible

Points 1 Is the study population identified and described? Are

eligibility criteria specified? Are the sample selection procedures clearly delineated?

Study Population Vulnerable population groups in Lebanon 5 Eligibility criteria To be eligible, a participant needed to be (1) resident of Tyr and

surrounding towns OR Palestinian refugee camps (2.5); (2) responsible for food preparation within household. (2.5)

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Sample selection procedures Tyre resident survey: probabilistic sampling of Tyre and 67

surrounding towns proportional to estimated size of city/village (2.5) Palestinian refugee survey: all 12 refugee camps were selected (2.5)

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2 What approach do the authors use to establish face validity?

To establish face validity, the authors utilized a qualitative study (focus group interviews) to ensure understanding of questions as intended and cultural appropriateness of the language used across geographic regions and range of beliefs represented by the target population.

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3 What type of sampling plan was used? Would an alternative sampling plan have been preferable? Was the sampling plan one that could be expected to yield a representative sample?

Sampling plan Cluster randomized sampling design

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Alternative sampling plan Since probabilistic sampling was used, the representativeness of the sample is not expected to be compromised. 2

Sampling plan yielding representative sample Tyre resident survey: probabilistic sampling is expected to yield a

representative sample of area residents. (1) Palestinian refugee survey: A random sample (probabilistic) is expected to yield a representative sample of refugee camp residents. (1)

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4 If sampling was stratified, was a useful stratification variable selected? If a consecutive sample was used, was the time period long enough to address seasonal or temporal variation?

Stratification Although the authors mention a stratified cluster sampling, there is no

mention of a stratification variable. 5

Consecutive sampling A consecutive sample was not used. 5 If cluster sampling was utilized, what were the clusters

and how was sampling done within clusters?

Clusters Tyre resident survey: town or village (2.5) Palestinian refugee survey: refugee camp (2.5) 5

Sampling method within clusters Tyre resident survey: households were selected using a random walk1 (2.5) Palestinian refugee survey: households were randomly selected. (2.5)

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5 How were people recruited into the sample? Does the method suggest potential biases?

Recruitment It seems that people were recruited by being invited to participate in

the survey. 5

Potential biases Given that households were selected randomly, the method does not suggest potential bias.

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6 Did some factor other than the sampling plan affect the representativeness of the sample?

No. Given the very high response rate for this study (85.1% for Southern Lebanese and 97.1% for Palestinian refugees), non- response bias is less likely to impact the representativeness of the sample.

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7 Are possible sample biases or weaknesses identified by the researchers themselves?

The researchers identify respondent bias as a limitation, especially among the Palestinian refugee sample. Participants might have modified their responses with the expectation of receiving assistance or benefits.

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8 Are key characteristics of the sample described (e. g., mean age, percent female)? If yes, please provide that information.

Yes. Table 1 included participant characteristics related to number of household members, income, and educational attainment. 5

9 Is the sample size sufficiently large to support statistical conclusion validity? Was the sample size justified on the basis of a power analysis or other rationale?

Statistical conclusion validity Statistical conclusion validity refers to the degree to which inferences

about relationships from statistical data analysis are correct. The sample size is large enough to detect statistical significance. No reference is made to the assumptions regarding the distribution of the variables so the associations detected may be erroneous.

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1 Random-walk sampling refers to a “method of random sampling in which the number of paces between sample points is determined by random numbers, usually drawn from random-number tables, and from each sample point a right-angle turn determines the direction of the next point, a coin being tossed to decide whether to turn left or right.” (Source: Encyclopedia.com)

Power analysis The authors mention that the data was pooled to increase sample

size and, thus, to increase the statistical power to detect variations in food insecurity (3). But it does not seem that power analysis was conducted a priori to determine the sample size. (3)

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10 Does the sample support inferences about external validity? To whom can the study results reasonably be generalized?

External validity External validity is supported by equivalence between the items on the AFFSS and CPS-FSS reflecting stability across languages and cultures.

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Generalizability Study findings support the use of the Arab Family Food Security Scale in similar vulnerable communities in other Arab countries and the Middle East. It can also be used in Arab speaking population groups outside the Arab world such as Syrian refugees in Europe, Iraqi refugees in the U.S., etc.

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