The dependent, or response, variable is the variable being tested in the model. You can either provide your dependent variable values in the input data set or you can have Joinpoint calculate them from other variables in the input data set (e.g. a crude rate can be calculated from variables with the count and the population).
Run Type
Calculated From Data File | This option should be selected if you want Joinpoint to calculate your dependent variable. Joinpoint can calculate Crude Rates, Age-Adjusted Rates, Proportions and Percentages. The table below documents which variables are required for each type of dependent variable. Please note that if Joinpoint calculates the dependent variable, it will also compute the associated standard errors. |
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Provided In Data File | This option should be selected if you are providing Joinpoint with your dependent variable values. For some analysis types, the standard error is also required. Please reference the table below for more information. |
Delay Adjusted Data | This option is only available if a SEER*Stat dictionary (DIC) file is used for the session that contains delay adjusted statistics. Joinpoint will read in and analyze the delay statistics for each cohort. See Delay Adjusted Statistics for more information. |
Delay & Non-Delay Data | This option is only available if a SEER*Stat dictionary (DIC) file is used for the session that contains delay adjusted statistics. Joinpoint will read in and analyze both the delay and non-delay statistics for each cohort. See Delay Adjusted Statistics for more information. |
Types of Dependent Variables Accepted by Joinpoint:
The following dependent variable types can be analyzed by Joinpoint:
Count | A count is typically a number of “events” (i.e. cancer cases or deaths. Joinpoint will accept counts in fractional form (e.g. 410.375). |
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Crude Rate |
A crude rate is the number of cases (or deaths) occurring in a specified population, usually expressed as the number of cases per 100,000 population at risk. Joinpoint will accept counts and populations in fractional form (e.g., 410.375). \(cruderate =\ \frac{count}{pop} \times\ 100,000\) |
Age-Adjusted Rate | An age-adjusted rate is a weighted average of crude rates, where the crude rates are calculated for different age groups and the weights are the proportions of persons in the corresponding age groups of a standard population. The age-adjusted rate for an age group comprised of the ages x through y is calculated using the following formula.
\(aarate_{x-y} = \sum_{i=x}^{y} \left[ \left( \frac{count_i}{pop_i} \right) \times\ 100,000 \times\ \left( \frac{stdpop_i}{\sum {}_{j=x}^{y} stdpop_j} \right) \right]\) Where count is the number of cases in the ith age group, popi is the relevant population for the same age group, and stdpopi is the standard population for the same age group. If counti and popi are both zero, Joinpoint treats that rate as zero. Joinpoint will not allow the unusual event where popi is zero but counti is non-zero. If counti is greater than zero and popi is zero, Joinpoint will set popi to be equal to counti in order to compute the interim crude rate. Joinpoint will accept counts, populations and standard populations in fractional form (e.g., 410.375). For a detailed explanation on how to compute age-adjusted rates, see How to Compute Age-Adjusted Rates. |
Proportion |
A proportion is a ratio of a numerator to a denominator where the result is between 0 and 1. Joinpoint will not analyze cohorts that have proportions greater than 1 when such proportions are calculated. Jointpoint will accept numerators and denominators in fractional form (e.g., 410.375). \(proportion = \frac{numerator}{denominator}\) |
Percent |
A percent is a fraction or ratio with 100 understood as the denominator. Joinpoint will not allow percentage values greater than 100 when such percentages are calculated. Jointpoint will accept numerators and denominators in fractional form (e.g., 410.375). \(percent = \frac{numerator}{denominator} \times\ 100\) |
Other | Select this category for all other types of numeric variables that do not fall into one of the previous categories (i.e. temperatures over time). |
Rates Per:
Though Crude Rates are usually expressed as the number of cases per 100,000, when Joinpoint computes Crude Rates, it provides users with several ‘rates per’ options. When age-adjusted rates are computed by Joinpoint, the same ‘rates per’ options are provided for the Crude Rate component. They are:
- 100
- 1,000
- 10,000
- 100,000
- 1,000,000
Standard Error Calculations:
When Joinpoint computes the Dependent Variable, the following formulas will be used to compute the associated standard errors.
Standard Error for Crude Rate
This calculation assumes that the counts have Poisson distributions.
\(SE_{crude} = \frac{\sqrt{count}}{population} \times\ 100,000\)
Standard Error for an Age-Adjusted Rate
This calculation assumes that the counts have Poisson distributions. Suppose that the age-adjusted rate is for an age group comprised of ages x through y.
\(SE_{AArate} = \sqrt{\sum_{i=x}^{y} \left( \frac{stdpop_i}{\sum {}_{j=x}^{y} stdpop_j} \right)^2 \times\ \left( \frac{count_i}{population_i^2} \right)} \times\ 100,000\)
Standard Error for Proportions and Percentages
For consistency, assume that percents are transformed to proportions before analysis.
\(SE_{proportion} = \sqrt{\frac{p_i \left( 1 - p_i \right)}{n_i}}\)
Where pi is the proportion and ni is the sample size of the ith observation.
\(SE_{percentage} = \sqrt{\frac{p_i \left( 1 - p_i \right)}{n_i}} \times\ 100\)
Edits performed on the Dependent Variable:
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When a session is executed, Joinpoint will first edit the input data file. For a list and description of all data errors and warnings produced by Joinpoint, please see the "Job Execution - Errors and Warnings" help section.
Variables:
One or more of the following variables will need to be specified in the input data file depending on the Calculated/Provided, Type, and Heteroscedastic Errors Options selections:
- Count Variable
- Population Variable
- Age-Adjusted Rate
- Standard Error - this variable can be found in within the Heteroscedastic/Correlated Errors Option box and is shown only for the applicable Heteroscedastic option.
- Adjustment Variable
- Standard Population
- Numerator Variable – this variable replaces the “Count” variable when appropriate
- Denominator Variable – this variable replaces the “Population” variable when appropriate
Joinpoint does allow any variable value to be provided in fractional form (e.g. 410.375).
Calculate | Type | Heteroscedastic Errors | Required Variables | Required Variables | Required Variables | Required Variables |
---|---|---|---|---|---|---|
No | Count | Constant Variance | Count | |||
No | Count | Standard Error | Count | Standard Error | ||
No | Count | Poisson Variance | Count | |||
No | Crude Rates | Constant Variance | Rate | |||
No | Crude Rates | Standard Error | Rate | Standard Error | ||
Crude Rates | Poisson Variance | n/a | ||||
No | Age-Adjusted Rates | Constant Variance | Rate | |||
No | Age-Adjusted Rates | Standard Error | Rate | Standard Error | ||
No | Age-Adjusted Rates | Poisson Variance | n/a | |||
No | Proportion | Constant Variance | Proportion | |||
No | Proportion | Standard Error | Proportion | Standard Error | ||
No | Proportion | Poisson Variance | n/a | |||
No | Percent | Constant Variance | Percent | |||
No | Percent | Standard Error | Percent | Standard Error | ||
No | Percent | Poisson Variance | n/a | |||
No | Other | Constant Variance | Other | |||
No | Other | Standard Error | Other | Standard Error | ||
No | Other | Poisson Variance | n/a | |||
Yes | Count | Constant Variance | n/a | |||
Yes | Count | Standard Error | n/a | |||
Yes | Count | Poisson Variance | n/a | |||
Yes | Crude Rates | Constant Variance | Count | Population | ||
Yes | Crude Rates | Standard Error | Count | Population | ||
Yes | Crude Rates | Poisson Variance | Count | Population | ||
Yes | Age-Adjusted Rates | Constant Variance | Count | Population | Age Group | Standard Pop |
Yes | Age-Adjusted Rates | Standard Error | Count | Population | Age Group | Standard Pop |
Yes | Age-Adjusted Rates | Poisson Variance | n/a | |||
Yes | Proportion | Constant Variance | Count | Population | ||
Yes | Proportion | Standard Error | Count | Population | ||
Yes | Proportion | Poisson Variance | n/a | |||
Yes | Percent | Constant Variance | Count | Population | ||
Yes | Percent | Standard Error | Count | Population | ||
Yes | Percent | Poisson Variance | n/a | |||
Yes | Other | Constant Variance | n/a | |||
Yes | Other | Standard Error | n/a | |||
Yes | Other | Poisson Variance | n/a |