SELECT
e.desc_entidade,
(SELECT DATA
    FROM agenda
    WHERE agenda.desc_agenda = 2
    AND e.id_entidade = agenda.id_entidade
    ORDER BY agenda.id_agenda DESC LIMIT 0, 1) AS data_ultima_consulta,
(SELECT DATA
    FROM agenda
    WHERE agenda.desc_agenda = 0
    AND e.id_entidade = agenda.id_entidade
    AND agenda.DATA > curdate() ORDER BY agenda.id_agenda ASC LIMIT 0, 1) AS data_proxima,
curdate() AS hoje

FROM (agenda) LEFT OUTER JOIN entidade AS e ON e.`id_entidade` = agenda.`id_entidade`
WHERE datediff( (SELECT DATA
    FROM agenda
    WHERE agenda.desc_agenda = 2
    AND e.id_entidade = agenda.id_entidade
    ORDER BY agenda.id_agenda DESC LIMIT 0, 1), agenda.DATA) > 30

GROUP BY e.id_entidade
ORDER BY e.`id_entidade` ASC