0
Original Article |

Outcome Study of Psychological Distress and Nonspecific Symptoms in Patients With Mild Primary Hyperparathyroidism FREE

Takahiro Okamoto, MD, MSC; Toshiko Kamo, MD, PhD; Takao Obara, MD, PhD
[+] Author Affiliations

From the Departments of Endocrine Surgery (Drs Okamoto and Obara), Hygiene and Public Health II (Dr Okamoto), and Psychiatry (Dr Kamo), School of Medicine, Tokyo Women's Medical University, Tokyo, Japan.


Arch Surg. 2002;137(7):779-783. doi:10.1001/archsurg.137.7.779.
Text Size: A A A
Published online

Background  Primary hyperparathyroidism is a common endocrinopathy. The appropriate management of its mild form, however, remains controversial.

Hypothesis  Mild primary hyperparathyroidism is associated with psychological distress and other nonspecific symptoms that improve following parathyroidectomy.

Design  Two-year prospective before-after study.

Setting  University hospital.

Patients  Twenty-six consecutive patients with mild hypercalcemia (<12 mg/dL [<3 mmol/L]) due to primary hyperparathyroidism, without osteitis fibrosa cystica or urolithiasis were enrolled from January 11, 1997, through April 21, 1998.

Intervention  Parathyroidectomy.

Main Outcome Measures  Primary outcome was psychological distress as measured by the 28-item version of the General Health Questionnaire. Secondary outcomes included body weight, joint pain, and occurrences of bowel movements and urination.

Results  Before surgery, 15 patients (58%; 95% confidence interval, 37%-77%) showed psychological distress (case group) while 11 patients did not (noncase group). A clinically and statistically significant reduction in the General Health Questionnaire score was detected at 3 months in the case group (−6.1; 95% confidence interval, −11.0 to −1.2), but the reduction was smaller (−1.9; 95% confidence interval, −6.9 to 3.0) at 24 months after surgery. No significant change in the General Health Questionnaire score was observed in the noncase group during the follow-up. No significant change was noted in any of the secondary outcomes.

Conclusions  Psychological distress was associated with mild primary hyperparathyroidism and was ameliorated after surgery. The improvement, however, was limited in extent and duration.

WITH THE increasing use of routine biochemical laboratory testing, primary hyperparathyroidism (PHPT) is frequently detected.1 This trend has resulted in an observed change in the clinical presentation of the disease, in that most patients show mild hypercalcemia without classical manifestations of osteitis fibrosa cystica or urolithiasis.2,3 This evolution is challenging the management of the disease, and the recommendation of surgery for such patients is open to debate. A regional survey3 showed that surgery was recommended as the initial management for 41% of patients diagnosed between 1965 and 1974 but for only 15% of those diagnosed between 1983 and 1992.

The US National Institutes of Health4 proposed criteria to recommend surgery for asymptomatic patients with PHPT; nevertheless, some physicians are more conservative than the recommendations suggest, while others advocate parathyroidectomy for almost all patients.58 Among endocrine surgeons, a significant variation was noted in the threshold for recommending surgery.9

Some researchers7,10,11 claim that patients with mild hypercalcemia due to PHPT report symptoms, when questioned in detail, of depression, constipation, polyuria, weight loss, and joint pain; other investigators,1214 however, do notagree. A systematic review15 of the literature revealed that the effect of surgery on such outcomes has never been fully elucidated with the relevant study population, namely, patients showing mild hypercalcemia without the classical manifestations.

The objective of the present study was to determine the extent of and the changes in nonclassical symptoms before and after parathyroidectomy in this particular patient population. Psychological distress was chosen as the primary outcome because it is an essential aspect of humans' well-being. Secondary outcomes included body weight, joint pain, and occurrences of bowel movements and urination.

DESIGN AND PROTOCOL

A prospective longitudinal study was conducted in patients with mild PHPT who were operated on and followed up for 2 years. The study was approved by the Ethical Committee of Tokyo Women's Medical University. All participants in the study gave written informed consent.

PATIENTS

To be classified as having mild PHPT, patients had to fulfill all of the following conditions (inclusion criteria): albumin-corrected serum calcium level less than 12 mg/dL (<3 mmol/L), no evidence of osteitis fibrosa cystica on x-ray films of the hands, and no history or evidence of urolithiasis. Patients with 1 or more of the following conditions (exclusion criteria) were excluded: multiple endocrine neoplasia, recurrent or persistent hyperparathyroidism, concomitant thyroid diseases, or a cognitive limitation.

From January 6, 1997, through April 30, 1998, 80 consecutive patients with PHPT underwent parathyroidectomy in the Department of Endocrine Surgery at Tokyo Women's Medical University. Because 37 did not fulfill the inclusion criteria and 8 patients met at least 1 of the exclusion criteria, 35 patients were potentially eligible subjects. Among them, 26 agreed to take part in the study (participants), while 9 patients never have a chance to be asked to participate for logistical reasons (nonparticipants).

MEASUREMENTS

Psychological distress was measured using the General Health Questionnaire (GHQ).16,17 It is a self-administered screening instrument designed to detect current diagnosable psychiatric disturbances, and it focuses on disruptions in normal function rather than on lifelong traits.16 A 28-item version (GHQ-28), 1 of several shorter forms of the GHQ, was used for the present study and includes 4 subscales (somatic symptoms, anxiety, social dysfunction, and severe depression). The GHQ scoring method of assigning weights of 0, 0, 1, and 1 to 4 response columns for each of the 28 items generates a potential total score between 0 and 28.16 For the Japanese GHQ-28, a cutoff value of 6 is used for psychological case identification, designating patients with a score of 6 or higher as cases.17 Reliability and validity of the GHQ-28 have been established, with a test-retest correlation coefficient of 0.90 and sensitivity and specificity in case identification of 90% and 86%, respectively, for a cutoff value of 6.16,17 It was also demonstrated that the GHQ-28 reflects changes in the severity of psychiatric disturbances over time.18

For the secondary outcomes, participants recorded their body weight and the degree of joint pain as assessed by an 11-point numerical rating scale.19 In addition, they were asked to keep a diary in which they counted the occurrences of bowel movements and urination for 3 consecutive days at each scheduled measurement.

All outcome measures were evaluated before and at 3, 6, 12, and 24 months after parathyroidectomy. The initial assessment was performed during the hospital stay just before the planned surgery, and follow-up evaluations were conducted by postal communications.

STATISTICAL CONSIDERATIONS

Characteristics of the participants and the nonparticipants were compared using the χ2 test for categorical variables and an unpaired t test for continuous variables. The mean preoperative GHQ score of the participants was compared with the reference value of the Japanese GHQ-28 (mean ± SD, 2.76 ± 2.31) using an unpaired t test.

Repeated-measures analysis of variance was used to examine the time trends in the outcomes. For the primary outcome, the GHQ total score and its 4 subscale scores were analyzed by multivariate repeated-measures analysis of variance. Multiple comparisons were made between the baseline and postoperative outcome measurements using Dunnett procedure. For occurrences of bowel movements and urination, mean values at each scheduled observation period were used for the statistical analyses.

Based on observations by Ormel et al,20 a minimally and clinically important change in the GHQ-28 score ranges between 3 and 6. When a type I error is set at 5% for a 2-tailed distribution, a sample size of 26 gives a power greater than 84% to detect that change using a paired t test, assuming that the SD of the change in the GHQ-28 score ranges between 3 and 5.20

The 95% confidence intervals (CIs) for proportions were constructed using binomial distribution. Commercially available statistical software (SSPS version 10.0J; SPSS Japan Inc, Tokyo, Japan) was used for all other analyses.21

CHARACTERISTICS OF THE STUDY POPULATION

Characteristics of the 26 participants, along with those of the 9 nonparticipants, are shown in Table 1. The mean ± SD level of serum calcium of the participants (10.7 ± 0.6 mg/dL [2.68 ± 0.15 mmol/L]) was significantly lower than that of the nonparticipants (11.4 ± 0.4 mg/dL [2.85 ± 0.09 mmol/L]) (P = .01). Although statistically insignificant, there were more women among the participants (23/26 [89%]) compared with the nonparticipants (5/9 [56%]) (P = .055). Nine participants (35%) required medications for comorbid conditions while 6 nonparticipants (67%) needed medications (P = .13).

Table Graphic Jump LocationTable 1. Preoperative Characteristics of the Participants and Nonparticipants

All of the participants underwent standard unilateral neck exploration and parathyroid tumor removal without any complications. Pathological diagnoses of the tumors were all single adenomas. None of the participants developed hypocalcemia requiring calcium or vitamin D supplementation, except for 2 who took calcium lactate or calcitriol for several days for slight numbness. Serum calcium levels of all the participants were within the normal range throughout the follow-up.

PSYCHOLOGICAL DISTRESS BEFORE SURGERY

At the initial assessment, the mean GHQ-28 total score of the participants was 8.6 (95% CI, 5.5-11.7), which was significantly higher than the reference value (P<.001). Fifteen subjects (58%; 95% CI, 37%-77%) were considered to be psychological cases while others were noncases. Baseline characteristics of the case group and of the noncase group are presented in Table 2. There was no significant difference between the 2 groups in age, sex, laboratory data, or the prevalence of comorbid conditions.

Table Graphic Jump LocationTable 2. Preoperative Characteristics of the Case and Noncase Groups*
CHANGES IN PSYCHOLOGICAL DISTRESS AFTER SURGERY

Three participants in the case group withdrew from follow-up evaluations of the outcomes. One took part in the preoperative assessment. The other 2 became unavailable after responding at the 3-month and 6-month evaluations, respectively (Table 3). They were excluded from the longitudinal analyses of the primary and secondary outcomes data.

Table Graphic Jump LocationTable 3. General Health Questionnaire Scores of Cases Who Withdrew From Follow-up Evaluations*

Multivariate-repeated measures analysis of variance of the GHQ scores showed significant changes in the time trends in the case group (P = .01) but not in the noncase group (P = .63). Changes in the GHQ scores from the preoperative assessment are summarized in Table 4. A significant decrease in the GHQ total score was noted at 3 months after surgery in the case group (−6.1; 95% CI, −11.0 to −1.2), but the change was not sustained at 24 months (−1.9; 95% CI, −6.9 to 3.0). For the subscale scores in the case group, significant reductions were observed in somatic symptoms, anxiety, and severe depression at 3 months after surgery. The extent of these reductions, however, became smaller as time passed after surgery, except for the depression subscale, for which the reduction was maintained throughout the follow-up. At 24 months after surgery, the proportions of participants whose total scores were at the cutoff value or higher were 83% (95% CI, 52%-98%) in the case group and 27% (95% CI, 6%-61%) in the noncase group.

Table Graphic Jump LocationTable 4. Mean Changes in the General Health Questionnaire Scores From the Preoperative Evaluation
SECONDARY OUTCOMES

Preoperative mean ± SD values for body weight, joint pain on the 11-point numerical rating scale, and occurrences of bowel movements and urination were 56.2 ± 7.8 kg, 2.6 ± 2.5, 1.2 ± 0.7, and 6.5 ± 2.1, respectively. Follow-up evaluations revealed no significant changes in any of the secondary outcomes (Table 5).

Table Graphic Jump LocationTable 5. Mean Changes From the Preoperative Evaluation (n = 23)

Although surgery has traditionally been the definitive treatment for PHPT, a recent predominance of patients with mild disease has called into question the need for parathyroidectomy.5 Because an abnormal test finding of mild hypercalcemia may not in itself be an indication for parathyroidectomy, clinical outcomes of surgery were examined to try to resolve this dilemma.

Psychological symptoms are associated with PHPT, including depression, anxiety, fatigue, concentration difficulties, and sleep disturbances.22 Such observations led to the formation of a hypothesis that PHPT causes psychological distress. There are some biological explanations to support the relationship.23,24 The effect of parathyroidectomy, however, has never been fully established: some researchers23,25,26 report that surgery is associated with improvement of the symptoms, while other investigators1214,27 report conflicting findings. In particular, data on patients with mild hypercalcemia are limited. A 1997 systematic review article15 revealed 3 studies that had used reliable and valid instruments to measure psychological distress in this patient population. Although PHPT with mild hypercalcemia is associated with distress, no longitudinal study with a sufficient follow-up had determined the outcome effects of surgery.15 In addition, no other study at the time of our investigation had reported on the outcomes of a study population without the classic symptoms. This prompted us to carry out a longitudinal study of this population in whom indications for surgery are controversial. In a study published in 1998, Pasieka and Parsons28 reported that patients with PHPT experienced improvements in their symptoms, including psychological ones, 1 year after surgery. This study, however, involved a population with general PHPT, not the mild form of the disease. Using the SF-36 health status questionnaire, Talpos et al29 measured quality of life in a randomized controlled trial of patients with mild PHPT who were allocated to groups with or without surgery. Although their study demonstrated that surgery provided some statistically significant improvements, it was not clear whether the observed changes in the SF-36 scores represented clinically important improvements.

The primary hypotheses for the present study were 2-fold: (1) mild PHPT is associated with psychological distress and (2) the distress is improved after parathyroidectomy. The results obtained were consistent with the hypotheses. However, because the improvement in the case group was not sustained during the follow-up, the association may not represent the causal relationship between the disease and the distress. The changes in the GHQ scores in the case group can be explained by alternative hypotheses. First, psychological symptoms may arise from stress as a general experience of having surgery.13 In a study conducted by Joborn et al,10 patients with probable PHPT with mild hypercalcemia who had not undergone parathyroidectomy showed little distress. The explanation, however, is weakened by the finding that preoperative patients with other diseases did not exhibit distress.28,30 Second, regression to the mean may play a role in the repeated measurements.31 However, the observed changes in the case group at 3 months after surgery were clinically important beyond statistical regression.20 Third, as Lundgren et al32 showed, symptoms such as joint pain, increased fatigue, loss of energy, and mental depression were commonly seen among healthy subjects; therefore, these symptoms in patients with mild PHPT may be coincidental, and the observed improvement may be a consequence of patients' expectations of the treatment. As shown in clinical studies33,34 of surgical treatment for angina pectoris, if improvements in subjective symptoms are due to such a placebo effect of surgery, the symptoms would be expected to recur several months after the operation. The 2-year follow-up in the present study was sufficient to compensate for this potential bias.

Generalizability of the present study is limited for 2 reasons. First, results from preoperative patients may not be applicable to patients who are managed conservatively. Second, the prevalence of psychological cases in the present study may be overestimated because there were more women among the participants compared with the nonparticipants. Scores on the GHQ tend to be higher in women than in men.16

Benefits of parathyroidectomy cannot be determined by conducting randomized controlled trials in which subjects are blinded to interventions, because such allocation would be unethical. Therefore, observational studies on various outcomes are necessary to establish appropriate management strategies for patients with mild PHPT.

We thank Akie Hattori for her managerial work.

This study was not supported by any external funding.

Corresponding author and reprints: Takahiro Okamoto, MD, MSc, Department of Endocrine Surgery, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.

Heath  H  IIIHodgson  SFKennedy  MA Primary hyperparathyroidism: incidence, morbidity, and potential impact in a community. N Engl J Med. 1980;302189- 193
Mundy  GRCove  DHFisken  R Primary hyperparathyroidism: changes in the pattern of clinical presentation. Lancet. 1980;11317- 1320
Wermers  RAKhosla  SAtkinson  EJHodgson  SFO'Fallon  WMMelton  LJ  III The rise and fall of primary hyperparathyroidism: a population-based study in Rochester, Minnesota, 1965-1992. Ann Intern Med. 1997;126433- 440
Consensus Development Conference Panel, National Institutes of Health, Diagnosis and management of asymptomatic primary hyperparathyroidism: consensus development conference statement. Ann Intern Med. 1991;114593- 597
Posen  SClifton-Bligh  PReeve  TSWagstaffe  CWilkinson  M Is parathyroidectomy of benefit in primary hyperparathyroidism? QJM. 1985;54241- 251
Davies  M Primary hyperparathyroidism: aggressive or conservative treatment? Clin Endocrinol (Oxf). 1992;36325- 332
Ljunghall  SHellman  PRastad  JÅkerström  G Primary hyperparathyroidism: epidemiology, diagnosis and clinical picture. World J Surg. 1991;15681- 687
Clark  OH Asymptomatic primary hyperparathyroidism: is parathyroidectomy indicated? Surgery. 1994;116947- 953
Sosa  JAPowe  NRLevine  MAUdelsman  RZeiger  MA Thresholds for surgery and surgical outcomes for patients with primary hyperparathyroidism: a national survey of endocrine surgeons. J Clin Endocrinol Metab. 1998;832658- 2665
Joborn  CHetta  JLind  LRastad  JÅkerström  GLjunghall  S Self-rated psychiatric symptoms in patients operated on because of primary hyperparathyroidism and in patients with long-standing mild hypercalcemia. Surgery. 1989;10572- 78
Clark  OHWiles  WSiperstein  AEDuh  QY Diagnosis and management of primary hyperparathyroidism: safety, efficacy and deficiencies in our knowledge. J Bone Miner Res. 1991;6(suppl 2)S135- S142
Rubinoff  HMcCarthy  HHiatt  RA Hypercalcemia: long-term follow-up with matched controls. J Chronic Dis. 1983;36859- 868
Posen  S Asymptomatic primary hyperparathyroidism: a case for conservative management. Aust N Z J Med. 1992;22161- 163
Fisher  JA "Asymptomatic" and symptomatic primary hyperparathyroidism. Clin Investigator. 1993;71505- 518
Okamoto  TGerstein  HCObara  T Psychiatric symptoms, bone density and non-specific symptoms in patients with mild hypercalcemia due to primary hyperparathyroidism: a systematic overview of the literature. Endocr J. 1997;44367- 374
Goldberg  DPWilliams  P A User's Guide to the General Health Questionnaire: GHQ.  Windsor, England National Foundation for Education Research, Nelson Publishing1988;
Nakagawa  YDaibo  I The Japanese Version of the General Health Questionnaire [in Japanese].  Tokyo, Japan Nippon Bunka Kagakusha1985;
Ormel  JKoeter  MWJvan den Brink  WGiel  R Concurrent validity of GHQ-28 and PSE as measures of change. Psychol Med. 1989;191007- 1013
Jensen  MPTurner  JARomano  JM What is the maximum number of levels needed in pain intensity measurement? Pain. 1994;58387- 392
Ormel  JKoeter  MWJvan den Brink  W Measuring change with the General Health Questionnaire (GHQ): the problem of retest effects. Soc Psychiatry Psychiatr Epidemiol. 1989;24227- 232
Not Available, SPSS 10.0 Application Guides.  Chicago, Ill SPSS Inc1999;
Rastad  JJoborn  CÅkerström  GLjunghall  S Incidence, type and severity of psychic symptoms in patients with sporadic primary hyperparathyroidism. J Endocrinol Invest. 1992;15(suppl 6)149- 156
Joborn  CHetta  JRastad  JÅgren  HÅkerström  GLjunghall  S Psychiatric symptoms and cerebrospinal fluid monoamine metabolites in primary hyperparathyroidism. Biol Psychiatry. 1988;23149- 158
Goldstein  DAChui  LAMassry  SG Effect of parathyroid hormone and uremia on peripheral nerve calcium and motor nerve conduction velocity. J Clin Invest. 1978;6288- 93
Chan  AKDuh  QYKatz  MHSiperstein  AEClark  OH Clinical manifestations of primary hyperparathyroidism before and after parathyroidectomy: a case-control study. Ann Surg. 1995;222402- 414
Siperstein  AEShen  WChan  AKDuh  QYClark  OH Normocalcemic hyperparathyroidism: biochemical and symptom profiles before and after surgery. Arch Surg. 1992;1271157- 1163
Brown  GGPreisman  RCKleerekoper  M Neurobehavioral symptoms in mild primary hyperparathyroidism: related to hypercalcemia but not improved by parathyroidectomy. Henry Ford Hosp Med J. 1987;35211- 215
Pasieka  JLParsons  LL Prospective surgical outcome study of relief of symptoms following surgery in patients with primary hyperparathyroidism. World J Surg. 1998;22513- 519
Talpos  GBBone  HG  IIIKleerekoper  M  et al.  Randomized trial of parathyroidectomy in mild asymptomatic primary hyperparathyroidism: patient description and effects on the SF-36 health survey. Surgery. 2000;1281013- 1021
Solomon  BLSchaaf  MSmallridge  RC Psychologic symptoms before and after parathyroid surgery. Am J Med. 1994;96101- 106
Streiner  DLNorman  GF PDQ Epidemiology. 2nd ed. St Louis, Mo Mosby1996;
Lundgren  ELjunghall  SÅkerström  GHetta  JMallmin  HRastad  J Case-control study on symptoms and signs of "asymptomatic" primary hyperparathyroidism. Surgery. 1998;124980- 986
Fish  RGCrymes  TPLovell  M Internal-mammary-artery ligation for angina pectoris: its failure to produce relief. N Engl J Med. 1958;259418- 420
Cobb  LAThomas  GIDillard  DHMerendino  KABruce  RA An evaluation of internal-mammary-artery ligation by a double-blind technic. N Engl J Med. 1959;2601115- 1118

Figures

Tables

Table Graphic Jump LocationTable 1. Preoperative Characteristics of the Participants and Nonparticipants
Table Graphic Jump LocationTable 2. Preoperative Characteristics of the Case and Noncase Groups*
Table Graphic Jump LocationTable 3. General Health Questionnaire Scores of Cases Who Withdrew From Follow-up Evaluations*
Table Graphic Jump LocationTable 4. Mean Changes in the General Health Questionnaire Scores From the Preoperative Evaluation
Table Graphic Jump LocationTable 5. Mean Changes From the Preoperative Evaluation (n = 23)

References

Heath  H  IIIHodgson  SFKennedy  MA Primary hyperparathyroidism: incidence, morbidity, and potential impact in a community. N Engl J Med. 1980;302189- 193
Mundy  GRCove  DHFisken  R Primary hyperparathyroidism: changes in the pattern of clinical presentation. Lancet. 1980;11317- 1320
Wermers  RAKhosla  SAtkinson  EJHodgson  SFO'Fallon  WMMelton  LJ  III The rise and fall of primary hyperparathyroidism: a population-based study in Rochester, Minnesota, 1965-1992. Ann Intern Med. 1997;126433- 440
Consensus Development Conference Panel, National Institutes of Health, Diagnosis and management of asymptomatic primary hyperparathyroidism: consensus development conference statement. Ann Intern Med. 1991;114593- 597
Posen  SClifton-Bligh  PReeve  TSWagstaffe  CWilkinson  M Is parathyroidectomy of benefit in primary hyperparathyroidism? QJM. 1985;54241- 251
Davies  M Primary hyperparathyroidism: aggressive or conservative treatment? Clin Endocrinol (Oxf). 1992;36325- 332
Ljunghall  SHellman  PRastad  JÅkerström  G Primary hyperparathyroidism: epidemiology, diagnosis and clinical picture. World J Surg. 1991;15681- 687
Clark  OH Asymptomatic primary hyperparathyroidism: is parathyroidectomy indicated? Surgery. 1994;116947- 953
Sosa  JAPowe  NRLevine  MAUdelsman  RZeiger  MA Thresholds for surgery and surgical outcomes for patients with primary hyperparathyroidism: a national survey of endocrine surgeons. J Clin Endocrinol Metab. 1998;832658- 2665
Joborn  CHetta  JLind  LRastad  JÅkerström  GLjunghall  S Self-rated psychiatric symptoms in patients operated on because of primary hyperparathyroidism and in patients with long-standing mild hypercalcemia. Surgery. 1989;10572- 78
Clark  OHWiles  WSiperstein  AEDuh  QY Diagnosis and management of primary hyperparathyroidism: safety, efficacy and deficiencies in our knowledge. J Bone Miner Res. 1991;6(suppl 2)S135- S142
Rubinoff  HMcCarthy  HHiatt  RA Hypercalcemia: long-term follow-up with matched controls. J Chronic Dis. 1983;36859- 868
Posen  S Asymptomatic primary hyperparathyroidism: a case for conservative management. Aust N Z J Med. 1992;22161- 163
Fisher  JA "Asymptomatic" and symptomatic primary hyperparathyroidism. Clin Investigator. 1993;71505- 518
Okamoto  TGerstein  HCObara  T Psychiatric symptoms, bone density and non-specific symptoms in patients with mild hypercalcemia due to primary hyperparathyroidism: a systematic overview of the literature. Endocr J. 1997;44367- 374
Goldberg  DPWilliams  P A User's Guide to the General Health Questionnaire: GHQ.  Windsor, England National Foundation for Education Research, Nelson Publishing1988;
Nakagawa  YDaibo  I The Japanese Version of the General Health Questionnaire [in Japanese].  Tokyo, Japan Nippon Bunka Kagakusha1985;
Ormel  JKoeter  MWJvan den Brink  WGiel  R Concurrent validity of GHQ-28 and PSE as measures of change. Psychol Med. 1989;191007- 1013
Jensen  MPTurner  JARomano  JM What is the maximum number of levels needed in pain intensity measurement? Pain. 1994;58387- 392
Ormel  JKoeter  MWJvan den Brink  W Measuring change with the General Health Questionnaire (GHQ): the problem of retest effects. Soc Psychiatry Psychiatr Epidemiol. 1989;24227- 232
Not Available, SPSS 10.0 Application Guides.  Chicago, Ill SPSS Inc1999;
Rastad  JJoborn  CÅkerström  GLjunghall  S Incidence, type and severity of psychic symptoms in patients with sporadic primary hyperparathyroidism. J Endocrinol Invest. 1992;15(suppl 6)149- 156
Joborn  CHetta  JRastad  JÅgren  HÅkerström  GLjunghall  S Psychiatric symptoms and cerebrospinal fluid monoamine metabolites in primary hyperparathyroidism. Biol Psychiatry. 1988;23149- 158
Goldstein  DAChui  LAMassry  SG Effect of parathyroid hormone and uremia on peripheral nerve calcium and motor nerve conduction velocity. J Clin Invest. 1978;6288- 93
Chan  AKDuh  QYKatz  MHSiperstein  AEClark  OH Clinical manifestations of primary hyperparathyroidism before and after parathyroidectomy: a case-control study. Ann Surg. 1995;222402- 414
Siperstein  AEShen  WChan  AKDuh  QYClark  OH Normocalcemic hyperparathyroidism: biochemical and symptom profiles before and after surgery. Arch Surg. 1992;1271157- 1163
Brown  GGPreisman  RCKleerekoper  M Neurobehavioral symptoms in mild primary hyperparathyroidism: related to hypercalcemia but not improved by parathyroidectomy. Henry Ford Hosp Med J. 1987;35211- 215
Pasieka  JLParsons  LL Prospective surgical outcome study of relief of symptoms following surgery in patients with primary hyperparathyroidism. World J Surg. 1998;22513- 519
Talpos  GBBone  HG  IIIKleerekoper  M  et al.  Randomized trial of parathyroidectomy in mild asymptomatic primary hyperparathyroidism: patient description and effects on the SF-36 health survey. Surgery. 2000;1281013- 1021
Solomon  BLSchaaf  MSmallridge  RC Psychologic symptoms before and after parathyroid surgery. Am J Med. 1994;96101- 106
Streiner  DLNorman  GF PDQ Epidemiology. 2nd ed. St Louis, Mo Mosby1996;
Lundgren  ELjunghall  SÅkerström  GHetta  JMallmin  HRastad  J Case-control study on symptoms and signs of "asymptomatic" primary hyperparathyroidism. Surgery. 1998;124980- 986
Fish  RGCrymes  TPLovell  M Internal-mammary-artery ligation for angina pectoris: its failure to produce relief. N Engl J Med. 1958;259418- 420
Cobb  LAThomas  GIDillard  DHMerendino  KABruce  RA An evaluation of internal-mammary-artery ligation by a double-blind technic. N Engl J Med. 1959;2601115- 1118

Correspondence

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).
Submit a Comment

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Web of Science® Times Cited: 18

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...
Articles Related By Topic
Related Topics
PubMed Articles