老年骨科良性疾病住院患者的营养不足和营养风险

目的　调查老年骨科良性疾病住院患者的营养状态,分析其与临床结局的相关性。方法　应用营养风险筛查2002（NRS2002)方法,前瞻性调查2012年4月1日至5月31日因患良性骨科疾病入院老年患者的营养不足和营养风险发生率,并分析其与临床结局的相关性。结果　共纳入520例老年骨科患者,平均年龄为（75 ± 7.09）岁,平均体质量指数（BMI）为(23.20±3.83) kg/m2,平均利手握力为（16.87±19.19）kg,平均上臂围为（25.62±3.81）cm,平均小腿围为（31.92±4.02）cm,其中与普通老年患者比较,高龄（≥80岁）老年患者握力下降明显［(13.58±15.92)kg比（18.48±20.42）kg,P=0.004］。520例患者进行营养风险筛查,营养不足发生率为9.31%（BMI≤18.5 kg/m2）,营养风险发生率为45.19%（NRS2002评分≥3分）;与普通（65~79岁）老年骨科患者比较,高龄（≥ 80岁）老年骨科患者营养不足和营养风险发生率均显著增加（13.97%比7.21%,P=0.024;52.38%比41.76%,P=0.024）,有营养风险者的感染并发症发生率更高（10.21%比5.26%,P=0.044）、住院时间更长［（11.66±5.76)d比(10.42±4.37)d,P=0.016］和住院费用更高［（2.028±1.811)万元比(1.639±1.362)万元,P=0.016］。结论　老年骨科良性疾病住院患者营养不足和营养风险发生率较高,并且可能导致临床结局恶化。     

头颈部恶性肿瘤患者放射治疗期间营养风险及营养不足发生率变化的纵向研究

目的　调查头颈部恶性肿瘤患者放射治疗期间营养风险及营养不足的发生率及其变化。方法　本研究为纵向观察性研究,采用方便取样法选择北京肿瘤医院接受放射治疗的头颈部恶性肿瘤患者为研究对象,在不同放射治疗阶段（放射治疗前、放射治疗中、放射治疗结束时）用营养风险筛查2002（NRS 2002）筛查患者的营养风险发生率,用患者参与主观全面评估（PG-SGA）和体成分测量调查其营养不良（不足）发生率,观察其变化。结果　有56例患者完成3次随访,随着放射治疗的进行,患者的NRS 2002评分逐次增加（1.64±1.09比2.30±1.06比3.14±1.07,χ2=46.639,P＜0.001）,营养风险的发生率亦逐次增加（21.43%比37.50%比71.43%,χ2=29.700,P＜0.001）,差异均有统计学意义。随着放射治疗的进行,患者的PG-SGA总分［1（1~13）比6（1~15）比12（1~18）,χ2=63.206,P＜0.001］及其中的体质量评分［0（0~4）比1（0~4）比3（0~6）,χ2=40.798,P＜0.001］、进食情况评分［0（0~2）比1（0~2）比2（0~4）,χ2=64.707,P＜0.001］、症状评分［0（0~7）比2（0~10）比6（0~11）,χ2=61.562,P＜0.001］均逐次增加,差异有统计学意义;患者在不同放射治疗阶段的营养不良发生率差异有统计学意义（χ2=64.999,P＜0.001）。40例患者体成分测量结果显示,随着放射治疗的进行,患者的各项测量指标的数值均逐次下降,差异有统计学意义;患者在放射治疗期间体质量丢失较多,且以去脂体质量丢失为主。结论　随着放射治疗的进行,头颈部恶性肿瘤患者营养风险及营养不足的发生率逐渐增加,且患者的体质量丢失以去脂体质量丢失为主,提示应关注头颈部恶性肿瘤患者在放射治疗期间的营养状况。     

营养咨询联合口服营养补充对食管癌放疗患者临床结局的影响

目的　评价营养咨询联合口服补充高脂肪、高蛋白肿瘤全营养配方食品（倍康素）对食管癌放疗患者营养状况和临床结局的影响。方法　选取80例能够经口进食且营养风险筛查2002（NRS2002）≥3分的食管癌放疗患者,随机数字表方法分为研究组（n=41,营养咨询+口服补充肿瘤全营养配方食品）和对照组（n=39,营养咨询）,比较放疗前后两组患者的能量摄入、营养状况、放疗不良反应发生率等。结果　放疗过程中,与对照组比较,研究组患者每天口服营养补充能量显著增加［（2 445±686） kJ比（1 747±456）kJ, P=0.003］;放疗前后对比,研究组患者前白蛋白和转铁蛋白水平显著升高［（17.35±5.83）mg/L比（20.15±6.02）mg/L, P=0.008;（213.74±52.66）mg/L比（264.19±43.78）mg/L,P=0.002］。此外,与对照组比较,研究组患者Ⅲ级放射性食管炎和Ⅲ级放射性皮肤损伤的发生率显著降低（24%比38%,P=0.000;27%比41%,P=0.000）。结论　营养咨询联合口服营养补充可改善食管癌放疗患者的营养状况,降低放疗相关毒副反应发生率,有助于改善临床结局。     

65岁以上住院患者焦虑情绪与营养风险的关系

目的 探讨65岁以上住院患者焦虑状态与存在营养风险的现况及两者的关系。方法 采用方便抽样的方法,选择2019年3 - 8月期间在宁夏回族自治区人民医院65岁以上住院患者为研究对象,共145例,记录入院后72 h内空腹静脉血检测的营养相关指标结果。采用营养风险筛查量表NRS2002评估患者的营养状态,以NRS2002评分≥3分的99例患者为存在营养风险组,以选择年龄和性别相匹配的NRS2002评分＜3分表示无营养风险组,共55例;采用独立样本t检验和χ2检验比较存在营养风险组与无营养风险组的组间均衡性,两组均行Zung氏焦虑自评量表（SAS）评分,比较两组患者的焦虑检出率情况。采用Pearson相关性和多因素logistic回归分析焦虑与存在营养风险的关系。结果 65岁以上住院患者存在营养风险和焦虑的检出率分别为62.17%和为45.5%。SAS平均评分为（49.56±11.71）分,其中不同年龄和不同居住地的患者SAS评分差异均有统计学意义（t = 2.379, P = 0.020）和（t = 3.007, P = 0.003）。存在营养风险组患者SAS评分为（55.6±10.19）分,高于无营养风险组的SAS评分（39.68±5.87）分,差异均有统计学意义（t = - 11.926,P＜0.001）;Pearson相关分析示:NRS2002评分与营养相关指标均呈负相关性（ 均r＜0,P＜0.001）;多因素条件logistic回归分析示:存在营养风险的住院患者发生焦虑情绪的风险比无营养风险组增加34.9%（OR = 34.929, 95%CI:9.738～125.285）。结论 65岁以上住院患者治疗期间容易存在营养风险,并且可能是导致焦虑情绪发生的重要因素之一,因而早期对住院患者进行营养风险筛查及营养干预可能有助于减少焦虑等负性情绪的发生。     

山东地区部分医院住院患者营养风险筛查和营养支持应用状况

目的 调查山东省部分地区不同规模医院住院患者营养风险、营养不良（不足）发生率及营养支持应用状况及相关并发症发生率.方法 以山东地区部分大、中、小医院2792例新住院患者为研究对象,进行营养风险筛查2002（NRS 2002）,记录患者营养支持应用情况、住院时间、感染性及非感染性并发症发生率.以NRS 2002≥3分为有营养风险,体重指数＜18.5 kg/m^2并结合患者临床情况判定为营养不足.结果 大、中、小医院新住院患者营养不足发生率分别为5.6%、1.6%、2.7%,差异有统计学意义（P=0.000）;营养风险发生率分别为27.3%、15.4%、18.3%,差异有统计学意义（P=0.000）;存在营养风险患者营养支持的应用率分别为51.5%、30.8%、20.9%,差异有统计学意义（P=0.000）;营养支持以肠外营养应用最多,大、中、小医院分别为72.9%、95.1%、100%,差异有统计学意义（P=0.000）.大医院483例新人院患者中无营养风险者并发症的发生率明显低于有营养风险的患者（P=0.000）;在有营养风险的患者中,接受营养支持患者的感染性并发症发生率明显低于无营养支持者（P=0.043）;在无营养风险的患者中,接受营养支持患者与无营养支持患者之间总并发症发生率差异无统计学意义（P＞0.05）.结论 采用NRS 2002对我国住院患者进行营养风险筛查是可行的,营养支持可以减少有营养风险患者并发症的发生.     

老年外科患者跌倒风险与营养状态的相关性

目的　调查老年外科患者的跌倒风险和营养状态,分析其相关性。方法　对2015年1至6月在北京医院普外科住院的年龄≥65岁的老年患者,应用Morse 跌倒评估量表评价其跌倒风险,应用人体物理测量指标、人体组分测定和营养风险筛查2002（NRS2002）等方法,评价老年患者的营养状态,并进行相关性分析。结果　共纳入383例患者,普通老年（65~79岁）患者314例,高龄（≥80岁）患者69例。与普通老年患者比较,高龄患者的握力［（24.53±8.09）kg比（30.57±8.48）kg］和4 m步速［（0.66±0.19）m/s比（0.84±0.20）m/s］显著降低（均P＜0.05）。高龄患者营养不足和营养风险发生率显著高于普通老年患者［15.9%（11/69）比7.0%（22/314）,56.5%（39/69）比38.2%（120/314）,均P＜0.05］。总体跌倒高度风险患者占33.9%（130/383）,高龄患者中跌倒高度风险者占44.9%(31/69),显著高于普通老年患者的31.5%（99/314）（P=0.036）;有跌倒高度风险的老年患者,其体质量指数［（22.33±1.82）kg/m2比(23.76±3.26)kg/m2］和握力［(24.95±8.56)kg比（30.72±8.39）kg］更低,营养风险发生率较高［46.9%（61/130）比38.7%（98/253）］（均P＜0.05）。结论　老年普外科住院患者存在较高的跌倒高度风险发生率,且与患者的营养状态相关联,应重视老年外科患者的护理和营养干预,预防跌倒发生,提高医疗质量。     

胃癌患者营养状况与小肠二肽转运载体1蛋白表达的相关性

目的　研究不同营养状态胃癌患者的小肠二肽转运载体1(PEPT1)蛋白表达,探讨其可能的调控机制。方法　以60例胃癌患者为研究对象,根据营养风险筛查2002（NRS 2002）评分分为有营养风险组（NRS 2002评分≥3分,n=18）及无营养风险组（NRS 2002评分＜3分,n=42）。术中取小肠黏膜标本,Western blot法检测小肠PEPT1蛋白表达。酶联免疫吸附法检测两组胃癌患者血清肿瘤坏死因子（TNF）-α的浓度。对Caco-2细胞采用不同浓度TNF-α（20、50、100 μg/L）处理,于不同时点（24、48、72 h）采用Western blot法检测Caco-2细胞PEPT1蛋白表达水平。结果　有营养风险组小肠PEPT1表达和血清TNF-α浓度均显著高于无营养风险组（0.63比0.23,P=0.000; 0.23 μg/L比0.17 μg/L,P=0.001）。在Caco-2细胞模型中,不同浓度TNF-α（20、50、100 μg/L）处理24 h后的PEPT1表达显著高于空白组（0.68比0.54,P=0.005;0.72比0.54,P=0.001;0.78比0.54,P=0.000）;TNF-α 50 μg/L处理不同时间（24、48、72 h）的Caco-2细胞PEPT1表达显著高于空白组（0.57比0.52,P=0.004;0.75比0.52,P=0.000;0.77比0.52,P=0.000）。结论　有营养风险的胃癌患者小肠PEPT1蛋白表达增加,其机制可能与TNF-α调控作用有关。     

营养状态和认知功能对PD患者日常生活能力的作用机制探索——基于中介效应和调节效应

目的 探讨营养状态和认知功能对PD患者日常生活能力的影响机制。方法 收集某院365例PD患者资料;采用简易营养评估量表（Mini Nutritional Assessment,MNA）、简易精神状态量表（Mini-Mental State Examination,MMSE）和统一帕金森病评分量表（Unified Parkinson’s Disease Rating Scale,UPDRS Ⅱ）分别评估PD患者的营养状态、认知功能和日常生活能力。采用Bootstrap法进行中介效应检验;采用协方差分析和简单效应分析检验调节效应。采用近似误差均方根（root-mean-square error of approximation,RMSEA）、赤池信息量准则（Akaike information criterion,AIC）、一致性赤池信息量准则（consistent Akaike information criterion,CAIC）和期望交叉验证指数（expected cross-validation index,ECVI）指标评估中介效应和调节效应模型的性能。结果 中介效应结果:路径MNA→MMSE→UPDRS Ⅱ的中介效应无统计学意义Z=-1.83（P=0.067）, β=-0.079, 95%CI(-0.164~0.006);路径MMSE→MNA→UPDRS Ⅱ的中介效应有统计学意义Z=-2.33（P<0.001）, β=-0.106, 95%CI(-0.195~-0.017),中介效应占比为16.48%。调节效应结果:MMSE和MNA交互效应系数为β=-12.792（P=0.013）,95%CI(-22.845~-2.740),t=-2.500。简单效应结果:潜在营养不良时,认知障碍组比认知正常组UPDRS Ⅱ评分平均高2.553分,95%CI为1.008~4.099;营养不良时,认知障碍组比认知正常组UPDRS Ⅱ评分平均高7.780分,95%CI为6.838~8.723。出现营养不良时,认知障碍与认知正常组的差值有统计学意义F=36.557（P＜0.001）,潜在营养不良时候,认知障碍与认知正常组的差值无统计学意义F=2.829（P＞0.05）。结论 MMSE→MNA→UPDRS Ⅱ的中介路径成立,但是中介效应较弱;PD发展机制中,营养状态介导并调节了认知功能对PD患者日常生活能力的影响。     

肠内联合肠外营养支持用于老年晚期消化道恶性肿瘤化疗患者的观察

目的 探讨肠内联合肠外营养支持对老年晚期消化道恶性肿瘤化疗的影响。方法 将2006年至2011年本院肿瘤内科收治的79例老年晚期消化道恶性肿瘤患者采用随机数字表法分为两组,治疗组（n=42）采用营养支持联合化疗,对照组（n=37）采用单纯化疗,入院后行营养风险筛查,2个化疗周期后比较营养状态、Karnofsky功能状态评分、毒性反应、院内感染率的变化。结果 两个周期化疗后,治疗组的体重指数 ［（19.00±3.31）kg/m2比（18.24±1.98）kg/m2,P=0.04］、白蛋白［（33.90±1.50） g/L比（29.90±2.38）g/L,P=0.02］、前白蛋白［（28.19±1.50)g/L比（25.51±8.38）g/L,P=0.01］、血红蛋白［（107.0±6.90)g/L 比（104.20±9.70）g/L,P=0.02］、淋巴细胞［（2.99±0.55)×109/L比（2.63±0.20）×109/L,P=0.03］均显著升高。化疗不良反应方面,治疗组骨髓抑制发生率明显低于对照组（28.57%比83.78%,P=0.00）;治疗组中有营养风险者的骨髓抑制发生率为31.03%,显著低于对照组的95.45%（P=0.00）,其他毒性反应差异无统计学意义。治疗组两次化疗后的院内感染发生率均显著低于对照组（0比10.81%,P=0.03;2.38% 比27.03%,P=0.02）。结论 老年晚期消化道恶性肿瘤患者化疗期间联合应用肠内加肠外营养支持有利于机体营养状况及体能的改善,减轻毒性反应,是院内感染发生的保护性因素。营养支持符合化疗患者的需求,具有安全、有效、合理的特点。     

外科胰腺肿瘤患者营养不足和营养风险发生率的前瞻性调查研究

目的　调查外科胰腺肿瘤患者营养不足和营养风险发生率。方法　对2014年1月至2015年12月,因各种胰腺肿瘤入住北京医院普外科,接受手术治疗的121例住院患者,根据肿瘤性质分为胰腺癌组和其他胰腺肿瘤组,主要应用营养风险筛查2002方法,前瞻性比较不同胰腺肿瘤患者的营养不足和营养风险发生率以及物理测量、体成分和外周血蛋白质水平等,记录临床结局。结果　121例符合入选标准的胰腺肿瘤患者进入本研究,胰腺癌组90例和其他胰腺肿瘤组31例,平均年龄（61.9±13.6）岁;平均体质量指数（23.20±2.95）kg/m2;上臂围（28.8±3.5）cm;肌肉组织量（44.6±7.4）kg;脂肪组织量（16.8±7.6）kg;两组在人体测量和体成分等方面差异无统计学意义（均P＞0.05）;胰腺癌组空腹血糖［（6.45±2.47）mmol/L］显著高于对照组［（4.95±0.79）mmol/L］（P＜0.001）,白蛋白［（39.0±4.7）g/L比(42.3±2.9)g/L,P＜0.001］,总蛋白［（62.8±6.2）g/L比(66.3±2.9)g/L,P＜0.001］和前白蛋白［（136.1±85.4）mg/L比(197.8±112.6),P=0.011］均显著低于对照组;营养不足发生率为4.1%,营养风险发生率78.5%;其中胰腺癌组营养风险发生率显著高于其他胰腺肿瘤组（91.1%比38.7%,χ2=36.525,P＜0.001）。结论　外科胰腺癌患者营养风险发生率较高,蛋白水平低和糖代谢异常,可导致住院时间延长。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.