documentclass[a4paper]{article}

    usepackage[top=0.5cm,bottom=1cm,left=1cm,landscape]{geometry}

    usepackage{tikz}
    usetikzlibrary{calc}

    begin{document}

    pagestyle{empty}

    tikzstyle{mbigblock} = [rectangle, draw, text width=5cm, text centered, minimum height=1em]
    tikzstyle{mbigblock2} = [rectangle, draw, text width=2.7cm, text centered, minimum height=2em]
    tikzstyle{mbigblock3} = [rectangle, draw, text width=2cm, text centered, minimum height=2em]
    tikzstyle{block}  = [rectangle, draw, text width=2.4cm, minimum height=1em]
    tikzstyle{blockcenter}  = [rectangle, draw, text width=2.4cm, text centered, minimum height=1em]
    tikzstyle{lblock} = [rectangle, draw, text width=5cm, minimum height=1em]
    tikzstyle{lblockcenter} = [rectangle, draw, text width=5cm, text centered, minimum height=1em]
    tikzstyle{rblock} = [rectangle, draw, text width=5cm, text centered, minimum height=2.85em]
    tikzstyle{rrblock} = [rectangle, draw, text width=5cm, text centered, minimum height=1.8cm]
    begin{tikzpicture}[node distance=2cm]

    % middle boxes
    node (m1) [mbigblock] {Public \ (Food and Health Bureau)};
    node (m2) [mbigblock2,below of=m1,node distance=1.3cm] {Government \ general revenue};
    node (m3)  [block,below of=m2, node distance=4cm] {textbf{Hospital \ Authority} \  vspace{5mm} -41 hospitals \ -GOPCs \  SOPCs\
    vspace{5mm}
    (predominantly Western \allopathic medicine) };
    node (m4)  [blockcenter,below of=m3, node distance =3.5cm] {Universal \ coverage};


    % left boxes
    node (l1) [lblock,left  of=m3,node distance=5cm] {textbf{Department of Health \ & Centre for Health \ Protection}\  vspace{5mm} -Disease prevention and \ control (communicable and \ non-communicable diseases)\ -Elderly health\ -Health education \-HIV/AIDS service \-Maternal and child health\-Port health\-Student health\-Tobacco control\-Tuberculosis service};
    node (l2) [lblockcenter,below of=l1,node distance=3.7cm] {General population};

    % right boxes
    node (r1) [rblock,right of=m1,node distance=6cm] {Private};
    node (r2) [mbigblock3,below of=r1,node distance=1cm] {Employers};
    node (r3) [mbigblock3,right of=r2, node distance=3cm] {Individuals};
    node (r4) [block,below of=r2,node distance=3.2cm,text width=2cm] {Private \ insurers/\ MCOs};
    node (r5) [mbigblock,below of=r4,node distance=1.25cm,text width=8cm] {Private providers};
    node (r6) [rblock,below left of=r5,node distance=1.7cm,text width=2cm] {Western \ allopathic\medicine\(73%)};
    node(r7) [rrblock,right of=r6, node distance=2.2cm, text width=2cm]{Chinese \ medicine \ (14%)};
    node(r8) [rrblock,right of=r7, node distance=2.2cm, text width=2cm]{Dental \ medicine\(10%))};
    node(r9) [rrblock,right of=r8, node distance=2.2cm, text width=2cm]{Laboratories\(3%))};
    node (r10) [mbigblock,below of=r5,node distance=3.25cm,text width=8cm] {Mostly individuals from middle and upper\ socioeconomic strata (except for Chinese medicine use)};
    % Flows
    draw[thick,->] (m2) -- (1.8cm,-3cm) --  node[block][right] {Minimal\out of\pocket\fees\(waived for\ the\ indigent)} (m3) ;
    draw[thick,->] (m2) -| (l1) ;
    draw[thick,->] (r2) -- (r4) ;
    draw[thick,->] (r3) |- (r4) ;
    draw[thick,->] (r4) -- (r5);
    draw[thick,->] (r3) -- (r5);



    end{tikzpicture}

    end{document}