Table 2.
Association between headache and emmetropia. (a) Contingency table; (b) Chi-squared test
| a. Contingency table | Headache | Total | |||
|---|---|---|---|---|---|
| Absence | Presence | ||||
| Emmetropia | Absence | Count | 23 | 47 | 70 |
| Stand. residues | -.9 | .8 | |||
| Presence | Count | 17 | 13 | 30 | |
| Stand. residues | 1.4 | -1.2 | |||
| Total | Count | 40 | 60 | 100 | |
| b. Chi-squared test | Value | df | Asymp. sig. (2 sides) | Exact sig. (2 sides) | Exact sig. (1 side) |
| Pearson Chi-squared | 4.728a | 1 | .030 | ||
| Continuity correctionb | 3.808 | 1 | .051 | ||
| Likelihood ratio | 4.681 | 1 | .030 | ||
| Fisher exact test | .044 | .026 | |||
| Linear-linear association | 4.680 | 1 | .031 | ||
| Number of valid cases | 100 | ||||
a.0 cells (,0%) have an expected count of less than 5. The minimum expected count is 12,12
b.Calculated only for a table 2 × 2