Frazier and Mosteller assert that

medical research could be improved by

a move toward larger, simpler clinical

Line trials of medical treatments. Currently,

(5) researchers collect far more background

information on patients than is strictly

required for their trials—substantially more

than hospitals collect—thereby escalating

costs of data collection, storage, and

(10) analysis. Although limiting information

collection could increase the risk that

researchers will overlook facts relevant

to a study, Frazier and Mosteller contend

that such risk, nerver entirely eliminable

(15) from research, would still be small in most

studies. Only in research on entirely new

treatments are new and unexpected variables

likely to arise.

Frazier and Mosteller propose not

(20) only that researchers limit data collection

on individual patients but also that

researchers enroll more patients in clinical

trials, thereby obtaining a more representative

sample of the total population with

(25) the disease under study. Often researchers

restrict study participation to patients

who have no ailments besides those being

studied. A treatment judged successful

under these ideal conditions can then

(30) be evaluated under normal conditions.

Broadening the range of trial participants,

Frazier and Mosteller suggest, would

enable researchers to evaluate a treatment’s

efficacy for diverse patients under

(35) various conditions and to evaluate its

effectiveness for different patient subgroups.

For example, the value of a

treatment for a progressive disease may

vary according to a patient’s stage of

(40) disease. Patients’ ages may also affect

a treatment’s efficacy.

第一段最后一句：

Only in research on entirely new

treatments are new and unexpected variables

likely to arise.

什么意思？

Although limiting information collection could increase the risk that researchers will overlook facts relevant to a study, Frazier and Mosteller contend that such risk, nerver entirely eliminable (15) from research, would still be small in most studies. Only in research on entirely new treatments are new and unexpected variables likely to arise.

尽管有限的信息收集可能使得这种风险增加--即调查者忽略和调查有关的一些事实，但是F和M认为这种从来就不能完全消除得风险在大多数的调查中仍然很小。只有在全新治疗方案中，新的未知的变量有可能增加（即风险会增加。）

Only in research on entirely new treatments are new and unexpected variables likely to arise.是一个倒装句，only引导的壮语从句在句首，主谓倒装。正常语序：Only in research on entirely new treatments new and unexpected variables are likely to arise