Your goal is to extract structured information from the user's input that matches the form described below. When extracting information please make sure it matches the type information exactly. Do not add any attributes that do not appear in the schema shown below.

```TypeScript

 { // Information on the clinical trial characteristics from the abstract
 conditions: string // The condition or disease being treated in the clinical trial
 drug_or_intervention: string // The drug or intervention used in the clinical trial
}
```


Please output the extracted information in JSON format. Do not output anything except for the extracted information. Do not add any clarifying information. Do not add any fields that are not in the schema. If the text contains attributes that do not appear in the schema, please ignore them. All output must be in JSON format and follow the schema specified above. Wrap the JSON in <json> tags.



Input:Randomized controlled trial of bilateral superficial cervical plexus block versus placebo in thyroid surgery.  Bilateral superficial cervical block during thyroid surgery can reduce postoperative pain but its value is unclear. This randomized clinical trial assessed the efficacy of such regional anaesthesia on postoperative pain after thyroid surgery performed under general anaesthesia. Patients undergoing thyroid surgery were randomized to one of four groups in a double-blind fashion. Patients received a cervical block with placebo or bupivacaine at the start or end of surgery. Postoperative pain, analgesic use and length of hospital stay were assessed. There were 159 patients eligible for analysis. The bupivacaine group had significantly less pain than the placebo group (P = 0.016). The timing of bupivacaine administration did not significantly influence pain (preoperative versus postoperative, P = 0.723). There was no difference between groups in the amount of analgesic used. Length of hospital stay was the same in the bupivacaine and placebo groups (P = 0.925) and when bupivacaine was administered at the beginning or end of surgery (P = 0.087). Bilateral superficial cervical block with bupivacaine combined with general anaesthesia significantly reduced postoperative pain after thyroid surgery. NCT00472446 (http://www.clinicaltrials.gov). Output:
{'conditions': 'Thyroidectomy', 'interventions': 'Procedure: superficial cervical block'}