Example of simulated family under a DD model.

<p>Capital letters designate disease alleles.</p

Percentage of datasets in which INT statistic is positive when unstratified lod score was positive.

<p>Percentage of datasets in which INT statistic is positive when unstratified lod score was positive.</p

Results from multipoint linkage simulation.

<p>Epistasis: disease is caused by two unlinked interacting loci; Heterogeneity; disease is caused by two independent loci. For each unstratified (Unstr) and stratified (Str) analysis and each model (DD/D+D, DR/D+R, RD/R+D and RR/R+R), the table contains: a) Family structure: number of families and subjects; b) Lod scores: mean (±sd) that satisfy selected row's condition; c) Percentages of datasets that satisfy selected row's condition.</p

INT statistics under selected unstratified Lod scores values.

<p>For each situation (Epistasis and Heterogeneity) and each model (DD/D+D, DR/D+R, RD/R+D and RR/R+R) the percentage of positive INT statistics (% pos INT) are shown. Also shown are the corresponding INT means (±sd) when the unstratified (Unstr) Lod scores satisfy the selected row's condition. LD between marker 4 and disease locus A was set to 1 and marker 4 allele frequency was matched to disease locus A allele frequency.</p

Distribution of INT statistic when unstratified lod score was at least 1.5 units.

<p>Vertical dotted lines emphasize the boundary between negative and positive INT values.</p

Lod score values varying the D' value between marker 4 and disease locus A.

<p>Unstratified lod score is represented by solid line and stratified lod score by dashed line. Horizontal dotted line identifies the threshold for significant evidence of linkage.</p

Simulation map.

<p>All recombination fractions, except those labeled, were set to 0.001.</p

Additional file 1 of The impact of primary headaches on disability outcomes: a literature review and meta-analysis to inform future iterations of the Global Burden of Disease study

Supplementary Material 1

Distribution of variables by country.

<p>Distribution of variables by country.</p

Hierarchical regression models to predict quality of life.

<p>Hierarchical regression models to predict quality of life.</p